There is no doubt that Obama will be the one framing the debate tonight and going forward.
What used to be the party of Lincoln, the fractured and fractious party of tin hat wearing tea baggers, paleocons, neocons, and a long laundry list of other factions of conservativism hasn't been the party of Lincoln for a long, long time, except in name only.
Lincoln was a liberal in his day; back in the 19th century, the Democrats were the conservatives. Republicans and Democrats both split off from the Democratic Republican party organized by Jefferson and Madison, with the Republicans originally calling themselves variously the American Republican Party which failed, the National Republican party, which failed, and Whigs, before the mid-19th century when they came up with just plain Republican Party, with a side experiment not unlike the Tea Party, appropriately called the Know Nothing party. Given the similarities, the Tea Party really should have revived that party identity.
Far from being the anti-slavery party, the modern GOP has gone so far right they have embraced racism, embraced xenophobia, embraced an unsuccessful form of laissez-faire vulture capitalism, and embraced a form of the most belligerent vulture-like militarism.
President Obama more closely represents the positive aspects of Lincoln, without the GOP rampant corruption that tainted it. The GOP has made a reactive and reactionary policy of opposing anything proposed by President Obama, and by refusing to cooperate with his administration in any way. The President has a 60% approval rating; the Republican members of Congress and especially the Tea Party generally have single digit approval, on a par with cockroaches and gonorrhea.
The conservatives who have hijacked the name of Republican are wrong in believing that Obama and the Democrats are their enemies. Sure, the majority of America is repudiating (or in the case of ignorant tea baggers, 'refudiating') their over-reach and extremism. But the real enemy of the right is their disconnect with reality, with facts, with reason, in favor of embracing their epic failure of ideology. In the context of Lincoln, the modern right are pretty much all 'RINOs', Republicans In Name Only, because the most definitely do NOT embody the values of Abraham Lincoln, or the party he led.