MADISON, Wis. - Wisconsin Gov. Scott Walker has raised more than $13 million in three months for a recall election, easily shattering the fund-raising record he set last year.

Walker became the target of a recall election after he pushed through legislation last year eliminating most public union workers' bargaining rights. His showdown with labor leaders and their Democratic allies made him a celebrity in Republican circles and enabled him to rake in cash at a pace never before seen in Wisconsin.

He set a record for fund-raising for a state office last year, when he pulled in $12.1 million. But that pales next to his fund-raising so far this year. Campaign-finance reports filed with state elections officials Monday show he collected $13.1 million between Jan. 18 and April 23. He spent $10 million over the period and had $4.8 million on hand.

A special state law allowing recall targets to raise unlimited amounts of money in their campaigns' early days helped Walker, but the pace of his fund-raising underscores how popular the governor is in conservative circles.

He attended a Christmas party thrown by conservative power broker Grover Norquist and raised money with Hank Greenberg, founder and former chief executive of American International Group, at his Manhattan office. He was in Oklahoma last month, mingling with the corporate elite and top Republicans at a fund-raiser cosponsored by Koch Industries, the oil company led by billionaire brothers who are top backers of conservative causes nationwide.

Walker faces political agitator Arthur Kohl-Riggs in a May 8 Republican primary. Five candidates are running in the Democratic contest. The survivor from each side will face off in a June 5 general election. None of Walker's challengers has been able to keep up in the money race.

Kohl-Riggs reported raising just $2,045 and spending $479 from Jan. 1 through April 23. He had $1,565 on hand.

The two Democratic front-runners, former Dane County Executive Kathleen Falk and Milwaukee Mayor Tom Barrett, didn't come close to Walker's totals. Falk's report showed she raised about $977,000 and spent $884,859 between Jan. 1 and April 23. She had $118,062 on hand. Barrett's report showed he had raised $831,508 and spent $808,975 during the same span. He had $475,496 in the bank.