Steve Kornacki thinks that, when he takes the podium to debate Paul Ryan on Thursday, Biden could help to halt Romney's post-debate momentum:
Biden is a far more skilled debater than Obama, and he finds himself matched against a particularly ripe target – the author of a far-right budget blueprint that’s become gospel within the Republican Party and that Democratic candidates across the country are eagerly running against. In other words, he has a chance to deliver the performance that Democrats were expecting from Obama.
Sophie Quinton notes Biden's strong showing against Sarah Palin in 2008:
Heading into the 2008 vice presidential debate, the assumption was that Biden would need to rein in his smarts and be patient with Palin…. Biden may have a tendency to misspeak when fired up by crowds, but he doesn’t tend to put his foot in his mouth during debates. And while a Biden gaffe during the debate might fire up Twitter, an inability on Ryan’s part to clarify the Romney ticket’s policies would ultimately be more damaging.
Doug Mataconis argues that the pressure to perform falls disproportionately on Ryan:
The bigger problem, though, is the fact that so many people on the right have been building up Ryan to the point where, arguably, even if his does his best his may end up disappointing people. From the moment that Mitt Romney named him as his running mate, conservatives have been looking forward to this debate with open glee. Ryan, they assume, will be able easily ride over a Vice-President that they see as mostly idiotic.