not whether publishers will publish lies (they will), or whether they will publish works by political hacks (ditto), or whether those works will be full of lies (double ditto), or whether those works are politically motivates (...well, you get the idea).
No, the interesting question is whether the mainstream press will provide the oxygen that is needed to allow such stuff to escape "the right wing echo chamber".
In the case of Swift, the answer was a resounding "yes". All the mainstream press treated the book seriously, leaving the impression that under the smoke there was some fire. It may have cost Kerry the election, and it certainly resulted in Corso's book. Having succeeded so brillaintly the first time, it is only natural for him to try again.
I think Corso is right: it will work again. Already, today's Washington Post has a "he said-she said" kind of story that, while critical of Corso's past in some respects, basically pits quotes from him against those from Obama campaign operatives. Expect to see more of this. The overall impression will be that Corso has some points, rather than that this is a political hatchet job that deserves to be suffocated at birth.
Will this sort of thing cost Obama the election? Hard to say. Obama is a better politician than the hapless Kerry, and McCain is a worse politician than Bush. But, the polls remain close, and the outcome will turn on which way the undecideds break.
What the Democrats need is their own Corso, who will bring up McCain's weaknesses (Keating, the divorce of his sick wife to marry an heiress, the flakiness and business dealings of that heiress, his shifting on almost every policy position, his temper, his serial lapses of memory, his hug of Bush...).
They also need to learn from Kerry's experience that the right-wing slime job will not go away on its own--our famous "liberal" press will ensure that it lives on. They have to get out in front of it. A good model is the first (Bill) Clinton campaign, where George Stephanopoulos made his name by vigorous counterattacks.