Deal told supporters in a speech that he is resigning "to devote my full energies" to the campaign for Georgia governor. He is in the midst of a hard-fought Republican primary that will be decided in July.
But resigning from Congress also means the end of the investigations into Deal by the House ethics panel, and the Office of Congressional Ethics, Melanie Sloan, executive director of Citizens for Responsibility and Ethics, tells TPMmuckraker. That's because once Deal steps down, he is no longer in the jurisdiction of the ethics committee.
Deal has denied wrongdoing in the case, which was sparked by an exposÃ© in the Atlanta Journal-Constitution last August.
The thumbnail version of the ethics charges is that Deal and his chief of staff allegedly intervened with state officials to try to preserve a no-bid deal that handed Deal's auto inspection firm loads of state business. The company reportedly brought in $1.5 million from its work for Georgia between 2004 and 2008.
"I think Deal is probably resigning there can be no investigation that comes to a conclusion that he did something wrong," says Sloan.
It's not clear why, other than freeing up time, it would be to Deal's advantage to resign from Congress instead of running out his term.
The Journal-Constitution points out that Deal is already spending a lot of time in Georgia, missing half of the votes in the House so far this year.
And a blogger at Peach Politics -- a conservative site that is friendly to one of Deal's challengers -- argues that Deal's move could dampen turnout in his own district on primary day:
... Deal is giving up the turnout advantage for being the sitting Congressman while the vote for his replacement takes place. GA law calls for a special election to replace Deal, and assuming the special election clears the field for the general election, having an unopposed incumbent running in the 9th when the primary vote for Governor takes place is a major campaign disadvantage for Deal.
Meanwhile, Republicans are angry with Deal because his departure makes it one vote easier for the Dems to pass health care reform.
Deal's campaign did not immediately respond to a request for comment.