Mark Schmitt, the Decembrist (a blog I like a lot) has advice for John Kerry about Negotiating With the Republicans, which amounts to, 'be a centrist, divide the Republican party'.
Brad DeLong, thinking like a smart White House staffer, thinks it is Good Advice. I beg to differ: it may be good January 2005 advice but it is rotten June 2004 advice.
I suspect that Brad's political reflexes were fixed by his service in the Clinton administration. Clinton never governed like he had a mandate (arguably, because he didn't have much of one the first time). He triangulated. He fogged about. He appointed Republicans as judges, and many Democrats who might as well have been Republicans. But that's a rotten way to govern if you have a choice when the other side uses a different play book. And Presidents early in their terms often do have a choice—even if they don't have a majority in either or both houses—so long as they can persuade Congress that they have a mandate, or create political conditions such that Congresspeople are unwilling to cross the President (think about why so many Democrats voted for Bush tax cuts).
Clinton exposed the mushiness of his political spine and his inability to use what political capital he had in the first days of his Presidency when he backed down on gay rights in the military. The signal to Congress was clear—if the guys who have a legal duty to salute and obey their commander in chief could roll the guy, there was no reason at all to give him an inch. He reaped the reward in the health care debate (OK, there were other good reasons [can you say “IRA”?] why it died, too). Clinton rarely if ever punished his enemies in Congress. He wasn't good enough at rewarding his friends, either. But that doesn't have to be the script for Kerry.
Suppose Kerry wins by a landslide — it could happen. Suppose he runs a campaign which is about restoring honor and decency to the White House, about repudiation of torture, sleaze, special interests, and, say, his limited health care plan. There's no reason to compromise on whatever he makes his signature issues. Certainly there's no reason to surrender preemptively now, before the votes are counted. Plenty of time for compromises later.
That said, if there issues where Kerry genuinely has a wedge in the Republican party, such as deficit reduction, by all means campaign on it and use it. But don't give up stuff we care about—until January at the earliest.