What you see in his budgeting proposals, I think, is the liberal equivalent of the conservative attempt to "starve the beast." In both the Reagan and Bush eras, Republicans passed tax cuts and ran up large deficits while hoping that by starving the federal government of revenue they would curb its long-run growth. Obama's spending proposals would effectively reverse that dynamic — they would create new spending commitments and run up large deficits, in the hopes that the dollars poured into health care and education will create a new baseline for government's obligations, which in turn will create the political space for tax increases on the middle class. Like the starve-the-beast approach, the Obama strategy puts off the hard part till tomorrow: Give them tax cuts today, conservatives said, and they'll swallow spending cuts tomorrow; give them universal health care, universal pre-K, subsidies for green industry and all the rest of it today, liberals seem to be thinking, and they'll be willing to pay for it tomorrow.
I think this is pretty much right, and it's exactly what conservatives are afraid of. As Bill Kristol knows all too well, social spending programs, once they get started, tend to be pretty popular. The odds of deep sixing, for example, national healthcare after it's up and running is essentially zero. And once it's up and running, taxes will follow because most Americans would rather see their taxes go up than their healthcare services go down.
Of course, this mostly applies to broad-based programs. Smaller ones are still hard to get rid of, but not impossible. It's the bigger ones that become third rails. Both Obama and the GOP are smart enough to know this, which is why Obama wants to swing for the fences and congressional Republicans want to become the Party of Nyet. If they don't stop him now, they never will.