Hedge fund manager behind ads critical of Jacobs

New York hedge fund manager Robert Mercer is the person behind TV ads that have criticized Republican U.S. Senate hopeful Mark Jacobs and praised rival Joni Ernst, according to a filling with the Federal Election Commission on Thursday.

American Heartland PAC has spent about $246,000 in the Republican primary race, according to the FEC, with a bit more than half going toward TV ads criticizing Jacobs.

Mercer is co-chief executive of Renaissance Technologies and donated $200,000 to American Heartland PAC, according to a filing with the FEC on Thursday. The filing is the last before the June 3 primary in which Ernst, Jacobs, former U.S. Attorney Matt Whitaker, college professor Sam Clovis and sales professional Scott Schaben are vying for the GOP nomination.

The American Heartland PAC ads have helped to even the playing field between Ernst and Jacobs, who at the end of March had put $1.6 million of his own money into the primary race and had been outpacing Ernst in TV advertising.

It's possible Mercer has donated more. The Thursday FEC filing reported contributions through last Wednesday, but earlier this week the American Heartland PAC reported independent expenditures in the Senate campaign that exceeded its total expenditures.

Mercer is a conservative who has been willing to donate a lot of money.

The Center for Responsive Politics said that he gave more than $5 million to conservative groups in the 2012 cycle, including $2 million to American Crossroads, which was founded by Karl Rove, and another $600,000 to the conservative Club for Growth.

The Washington Post also reported he's a member of the NRA, which has endorsed Ernst's candidacy.

Earlier this week, when the PAC began running pro-Ernst ads, the Jacobs camp called it a 'faceless special interest group” that was covering for Ernst.

In its filing, American Heartland said it had raised $205,000 in an approximately six-week period ending May 14, and spent nearly $198,000.

It had $7,600 in cash on hand as of last week.