In a column for The Daily Beast Brett O'Donnell, who coached Mitt Romney in the later debates of the Republican primary, says what viewers should watch for tonight:
"The first 30 minutes of the first debate are the most important. That will set in motion the narrative, and help determine whom voters perceive to be winning the debates. It’s hard to recover from a bad first outing. ...
"We should also pay attention to which candidate puts the other on the defensive. Neither man is particularly effective when on his heels."
O'Donnell also brushed aside the low-expectation game both sides are playing, noting that both Romney and Obama are "highly skilled orators."