John Avlon sees tonight's debate as crucial. So does Steve Kornacki:
Perry’s candidacy seems to be at a pivot point: Will he bounce back, assuage all of the concerns he’s raised among conservative leaders and activists and reassert himself as the right’s chief alternative to Romney? Or will things go from bad to worse, with Perry permanently marginalized as just one of several Romney alternatives? The week we are now starting, which will feature the first debate since his Orlando debacle and a major Perry speech on the economy, may be crucial in determining which direction he goes.
Nyhan isn't counting Perry out:
Going forward, Perry's principal challenge is to stay viable so that more elites don't defect to Romney. He is well-funded and has a favorable primary calendar. Regardless of his standing in national polls, he has a decent chance to mount a comeback against Romney because support in multi-candidate primaries is so fluid. When there are relatively minor ideological differences between candidates, it's possible to make rapid gains as voters shift to their second or third choices for strategic or stylistic reasons. If Perry can adapt to the rigors of a national-level campaign, his odds of consolidating enough of the anti-Romney vote to win the nomination are significantly better than the current Intrade estimate of 18.9%.
The Dish 