Former Commerce Secretary William Daley isn't running for Senate, after all.

The Democrat told the Chicago Sun-Times that he has aborted a planned run after rethinking his family situation, and he won't challenge state Treasurer Alexi Giannoulias in the Democratic primary for Sen. Roland Burris's (D-Ill.) seat.

"I was gung-ho, and hired pollsters and talked to fund-raisers and planned to make an announcement in mid-April," Daley told the Sun-Times. "But I'm getting remarried in June and decided I want to take a new tack in my life. I just don't want to live a commuter life back and forth from Washington."

Daley, the brother of Chicago Mayor Richard M. Daley (D), could have been a strong general election candidate for the seat, but his presence in the primary likely would have let to a difficult nominating contest for Democrats. There's still a possibility that occurs, but Daley's exit makes Giannoulias's path quite a bit clearer.

The turnabout wasn't terribly surprising for some Illinois Democrats. Daley has indicated interest in running for office before, only to back out.

Burris hasn't said whether he will run, but he is polling so low and raising so little money that he is unlikely to be a major factor in the primary even if he did.

On the GOP side, Rep. Mark Kirk (R-Ill.) has said he will decide by the end of the month whether to run for Senate. Kirk would be a formidable candidate in the general election, having raised large sums of money and held down a Democratic-leaning district in recent years.

-Aaron Blake