At this point, the only force that continues to pose an effective threat to a progressive agenda is the Democratic Party. Not the party institution as a whole, necessarily; it remains at least nominally devoted to the progressive program. However, its current status as the big-tent party necessarily means that it is composed of a large array of different interest groups.
This is important because of the Republican Party’s determination to use the filibuster to its fullest means that 60 votes are necessary for any important piece of legislation. I’m not complaining; I think that’s what Republicans should do, as long as its politically wise for them to do so. Their constitutents didn’t elect them to roll over and do what Obama says, they elected them to represent their conservative beliefs. It was unseemly for the Democrats to never stand up to the White House during the Bush years, and it would be similarly silly and antidemocratic to expect the Republicans to do the same. This, however, means that 60 votes are a practical necessity.
And Democrats from West Virginia, a big coal-producing state, will be leery of cap-and-trade for the harm it would do their industries. And the Democrats from Iowa will be similarly set against reform of farm subsidies. And Democrats from New York (I’m looking at you, Chuck Schumer) will fight tooth and nail to prevent any diminuition of the political power of the financial industry. At this point, it’s unrealistic to worry about the Republicans preventing a serious obstacle to Obama’s stated agenda. I’d say it’s more likely it’ll die the death of a thousand cuts, victim of the President’s alleged allies.