Popular Virginia Gov. Bob McDonnell (R) has endorsed former Sen. George Allen (R-Va.) as expected.

"George has always looked for innovative and bold solutions to help improve the lives of our fellow citizens. He did that as governor and as senator. And we need George Allen's optimistic, results-oriented leadership working for us in Washington again," McDonnell said.

The endorsement is unsurprising, but in a tight Senate race, McDonnell's high popularity in the state could help Allen a bit.

McDonnell played a big part in Republicans winning control of the Virginia Statehouse in this week's elections, and has been touted as a possible vice presidential nominee because of his sky-high popularity in the swing state. Recent polls show that two-thirds of Virginians approve of the job he's doing in the state.

Allen is locked in a tight battle against former Gov. Tim Kaine (D-Va.), who has led him narrowly in recent polls.