The Obama campaign has nabbed a robocall left on the voicemail of a Nevada supporter that refers to Obama as "Barack Hussein Obama" four times. No word on who is funding the ad.
On the other side, Bill Clinton, top Clinton ally Terry McAuliffe, and other Clinton surrogates are alleging that union officials are intimidating union members into caucusing for Obama. They are claiming that Clinton-friendly union members are being told to stay away from the caucuses. (This, by the way, will have the effect of delegitimizing the caucus if Obama wins. That is likely the point of the Clinton camp's agitating.)
All of this builds on the nasty radio ad Obama supporters are airing in Spanish.