There is something dramatic happening at the US Senate, per Politico.

Sen. Chris Murphy (D-Conn.) launched a talking filibuster on the Senate floor — which was quickly joined by fellow Democrats — in an effort to pressure Republicans to accept legislation that would deny suspected terrorists from purchasing firearms and require universal background checks.

...

I'm going to remain on this floor until we get some signal, some sign that we can come together on these two measures, that we can get a path forward on addressing this epidemic in a meaningful, bipartisan way,” Murphy continued on the Senate floor on Wednesday, after he first started his filibuster at about 11:20 a.m.

Watch live, courtesy of NBC News.

Elizabeth Warren Just Endorsed Hillary Clinton

In an interview with the Boston Globe this evening, Sen. Elizabeth Warren formally endorsed presumptive Democratic presidential nominee Hillary Clinton:

“I’m ready,” said Warren in an interview with The Globe Thursday evening. “I’m ready to jump in this fight and make sure that Hillary Clinton is the next president of the United States and be sure that Donald Trump gets nowhere near the White House.”

Earlier in the evening, Warren gave an "I'm going to light you on fire and burn you to the ground" speech attacking Donald Trump at the American Constitution Society of Law and Policy.

The Massachusetts senator (who also happens to be the left's secret internet girlfriend) is supposed to appear tonight on The Rachel Maddow Show (Maddow is also a secret internet girlfriend of the left) to talk about why she didn't endorse the left's secret internet boyfriend, Bernie Sanders. (The left gets around…in secret…on the internet.) I'll update this with video when that happens.

UPDATE: Wow, that was a really powerful interview Warren just gave on The Rachel Maddow Show.

Here's a clip from it. I'll post the rest as soon as MSNBC posts it.

Mother Jones' Josh Harkinson reported earlier today that the Trump campaign selected white nationalist leader William Johnson as a delegate in California.

Trump campaign spokeswoman Hope Hicks just issued this statement about it to the Washington Post:

Yesterday the Trump campaign submitted its list of California delegates to be certified by the Secretary of State of California. A database error led to the inclusion of a potential delegate that had been rejected and removed from the campaign’s list in February 2016.

Read Harkinson's full story.

UPDATE, 5:48 p.m. ET: "Database error" was apparently the Trump campaign's second attempt at an explanation.

Today is Cinco de Mayo, and here's what presumptive GOP nominee Donald Trump tweeted to celebrate the occasion:

 

Stop tweeting. 

Ted Cruz may be mathematically eliminated from clinching the Republican presidential nomination before the convention, but that didn't stop the Texas senator from announcing a running mate on Wednesday: Carly Fiorina, the former CEO of Hewlett-Packard. Fiorina, who dropped out of the Republican presidential race after the New Hampshire primary and previously lost a US Senate race in California, is a notable pick not just because she is a woman, or because she previously criticized Cruz for saying "whatever he needs to say to get elected," but because of her past experience—she would be the first vice president in 76 years to have ascended to the post without previously holding elected office.

The last time a major party picked a vice presidential nominee without legislative or gubernatorial experience was in 1972, when Democrat George McGovern chose Sargent Shriver, who had previously run the Peace Corps and worked on President Lyndon Johnson's "war on poverty." But you have to put an asterisk next to that, since Shriver was chosen only after McGovern's original running mate, Sen. Thomas Eagleton, resigned amid reports about his previous mental health treatments. Four years earlier, Alabama Gov. George Wallace selected as his running mate Air Force General Curtis LeMay, but Wallace, a longtime Democrat, had chosen to run (and lose) under the American Independent Party.

To find a running mate with no experience in elected office who actually won, you have to go back to 1940, when Franklin D. Roosevelt named Agriculture Secretary Henry Wallace as his second vice president, following eight years of John Nance Garner. Prior to that, Calvin Coolidge tapped Charles Dawes, President Warren Harding's budget director, to be on his victorious ticket in 1924. Dawes had lost a Senate race 23 years earlier and written a hit song in the interim, before being dragged into the executive branch. Dawes himself seemed to recognize his lack of qualifications. "I don't know anything about politics," he said after being selected as Coolidge's running mate. "I thought I knew something about politics once. I was taken up on the top of a 20-story building and showed the promised land—and then I was kicked off."

But okay, both of those vice presidents had some experience in the executive branch. The last true outsider to win was in the 19th century. Prior to becoming James A. Garfield's running mate in 1880, Chester A. Arthur had no political experience other than stints as port collector of New York City and chairman of the state Republican Party. In a nice bit of symmetry with Cruz's campaign, Arthur's future presidential campaign was marred by allegations that he was ineligible because he was born in Canada.

A day after losing to Hillary Clinton in four of five primaries in the Northeast, Bernie Sanders announced his campaign will soon start laying off "hundreds" of its staff members, the New York Times reports.

"We have had a very large staff, which was designed to deal with 50 states in this country," Sanders said in an interview with the Times. "Forty of the states are now behind us. So we have a great staff, great people."

The cuts to his staff, however, do not signal he is planning to bow out of the race anytime soon, the Vermont senator said. Instead, Sanders maintained he would remain in the race for the Democratic nomination at least until the end of the summer, and he hopes to rehire laid-off staff members eventually.

Five people familiar with the cuts also confirmed the news to Politico, hinting that Sanders was preparing to shift gears and potentially focus the rest of his campaign on influencing Clinton's platform.

In an announcement scheduled for later this afternoon, Sen. Ted Cruz will name former Hewlett-Packard CEO Carly Fiorina as his running mate if he secures the Republican nomination, multiple outlets are reporting.

This is a breaking news post. We will update with more as information becomes available.

State Sen. Jamie Raskin won Tuesday's Democratic primary in Maryland's eighth congressional district. But the bigger story is who lost—that would be David Trone, a wine retailer who spent $12.7 million of his own money in the hopes of winning the seat.

Trone, running in a district that includes the affluent Washington, DC, suburbs in Montgomery County, set a record for most money spent by a self-funding congressional candidate to win a House seat. (The previous record was $7.8 million, and that included both a primary and a general election; as of early April, Raskin's campaign had spent a little more than $1 million.)

The irony is that Trone was running as a campaign finance crusader. Much like Donald Trump, who cites his $35 million investment in his campaign as proof he can't be bought, Trone believed his enormous personal wealth would insulate him from charges of corruption. "I certainly could have raised enough money to fund a competitive campaign," he said in a full-page Washington Post ad two weeks ago, when he had only spent a pedestrian $9.1 million. "But the PACs, lobbyists and big dollar donors who give money would expect special attention. No matter how well-intentioned, those contributions and the candidates who take them are part of the reason Washington is broken."

That message carried him to the brink of success—or maybe it was just the deluge ads—but in the end, money alone didn't cut it. Trone won by large margins in the two counties that comprise a smaller portion of the district, but Raskin held a sizable edge in his home county, Montgomery. Trone's final receipt: a little more than $400 per vote.

Donald Trump dominated all five states in Tuesday's East Coast Republican primaries, a sweep that brought him at least 105 delegates and pushes him further along his path to securing the Republican presidential nomination and avoid a contested convention.

The Republican front-runner celebrated his impressive night from Trump Tower in New York, surrounded by his family and supporters including New Jersey Gov. Chris Christie, where he declared the Republican primary race all but over. He also continued his recent calls for Gov. John Kasich and Sen. Ted Cruz to end their campaigns.

"I consider myself the presumptive nominee, absolutely," Trump told reporters. "Senator Cruz and Governor Kasich should really get out of the race."

The real estate magnate went on to ridicule his two rivals in light of their recent announcement that they were uniting to defeat Trump and force a brokered convention—a strategy that started to collapse a day after it was announced.

"Governor Kasich and Senator Cruz have really, really hurt themselves with a faulty deal," he said. "Politicians, all talk, no action."

When asked about reports he would soon be striking a more "presidential" tone, Trump hinted that although he might act differently, his "thought process" would remain the same.

"If you have a football team and you're winning, and you make it to the Super Bowl, you don't change your quarterback," Trump said.

Trump concluded his victory speech by suggesting the only factor driving Hillary Clinton's success is the "woman's card" and that if she were a man, she wouldn't be able to get even 5 percent of the vote. In her victory speech, Clinton referred to Trump's previous reference to her playing the "woman's card" and said that if that meant standing up for equal pay for equal work, and health care for women, "deal me in."

Kansas Gov. Sam Brownback

Kansas Gov. Sam Brownback announced on Tuesday that Kansas is withdrawing from the federal government's refugee resettlement program over concerns that Syrian refugees could be security threats.

"Because the federal government has failed to provide adequate assurances regarding refugees it is settling in Kansas, we have no option but to end our cooperation with and participation in the federal refugee resettlement program," Brownback said in a press release.

Brownback had already issued an executive order in November stating that "no department, commission, board, or agency of the government of the State of Kansas shall aid, cooperate with, or assist in any way the relocation of refugees from Syria to the State of Kansas." Tuesday's announcement would apply to refugees from any country. But while the move sounds drastic, it's mostly a symbolic act that will have little on-the-ground impact for refugees or public safety.

For one, pulling out of the federal resettlement program doesn't mean refugees won't be allowed to live in Kansas. While Indiana and other states have tried to bar Syrians from entering their borders, they aren't actually able to do so. Like any other visa holders, refugees are able to go anywhere in the United States they'd like. It also doesn't mean that support for refugees who are currently living in Kansas or may move there will dry up. The funds that state agencies use for refugee aid are almost entirely federal money, and the Department of Health and Human Services retains control over the funds even if state employees or agencies don't take part. In those cases, Health and Human Services simply appoints another organization to administer the money. "This is the situation in some other states, usually because their resettlement program is very small," says Stacie Blake, the director of government and community relations at the US Committee for Refugees and Immigrants, one of the nonprofit groups that resettles refugees. "The money is not 'lost.'"

According to data from the State Department, only five Syrians have settled in Kansas since October last year.