The Republicans will never vote in favor of a bill that will give President Obama a political "win."
Forget single-payer, public options, or co-ops: the President could push for a healthcare bill that cuts taxes for the wealthy and reduces the size of government to that of a peanut, and the Republicans will vote against it. The birthers, the deathers are all the same way: the president could declare a federal NRA holiday --- Happy Gun Day! --- and they will still scream and shout and compare Obama to Hitler.
Trying to reason with them, compromise with them, or appeal to them is like, as Barney Frank said, talking to a dining room table. They have too much invested in Obama losing to ever participate in actual governance.
Although I can understand and appreciate Obama's desire to "cross the aisle," it is all just wasting time and political capital. Obama's best chance is to put forth the best healthcare plan possible, the one most likely to provide real reform and relief, and to hammer away at the Blue Dogs until they're in line.
(Thank you for letting me rant.)