President-elect Barack Obama has cut a 60-second radio spot for former state Rep. Jim Martin (D), who is vying against Sen. Saxby Chambliss (R) in the Dec. 2 Georgia Senate runoff.

The ad, which is accompanied by upbeat music, features Obama thanking voters for embracing his agenda of change, but then reminds them that “the elections aren’t over.”

Obama goes on to say that Martin supports his middle-class tax cut proposal.

“Jim Martin’s a man of his word, and I know he’ll do everything he can to help me change Washington,” the president-elect continues.

The ad will go up statewide on Friday.

The Obama ad is the latest development in an increasingly tense skirmish, as both parties work feverishly to push their candidate across the finish line. Several top-flight political celebrities have campaigned alongside Chambliss and Martin, and the two parties are spending heavily there.

But it was unclear until Thursday whether Obama would invest any of his political capital and get directly involved in the race. On Thursday evening, Martin campaign officials continued to hold out hope that Obama would visit the state personally before the runoff.

On Election Day, Chambliss fell just short of the 50 percent of the vote that he would have needed to avoid a runoff. Although Obama lost Georgia to Sen. John McCain (R-Ariz.), he got 47 percent of the vote there — more than any Democratic presidential nominee since Georgia-born former President Jimmy Carter in 1980.