This could be a key moment in this year's election cycle:  Jim Webb's GI Bill increasing the educational benefits for Iraq and Afghanistan veterans will come up for a vote in the Senate as part of the emergency war funding bill.  There will be a lot of agenda-masking legislative tactics, but Senators' positions on this bill will be key marker for them in on veterans' issues for the campaign. 

This is a particularly high stakes day for Senator McCain.  He has opposed the Webb bill, offering his own cheap immitation,  but has been trying to negotiate a compromise that lets him come back in out of the cold.  If he ends up opposing Webb today, he will have fundamentally undercut his claim on the loyalty of veterans, a vulnerability that Senator Obama is well prepared to exploit (see his great West Virginia speech on veterans issues )

Politico sets the scene well.