John McCain has offered to come off the campaign trail if Congress will go back into session. Congress has adjourned for the traditional August recess.
Why then, has he not been present since April 8? Recall that he had long since locked up the GOP nomination by the last time he cast a vote in the Senate, while Barack Obama, despite having to campaign until June to lock up his nomination has still found the time to come into the Senate and cast several votes during that time, including the medicare reimbursement bill for doctors, a bill that Senator McCain conveniently skipped so he wouldn't have to take a position on a controversial issue.
It seems that if John McCain has 'generously' offered to come off the campaign trail to go to work, then he should have done so at least once in the past four months while the Senate was actually in session. In fact if he'd picked the right day he might even have met Senator Obama while he was taking time off the campaign trail to cast at least a few votes.