Multiple news sources have reported that a Riverside man may have played a role in the decision of the front-runner in the race for speaker of the U.S. House of Representatives to drop out of that race.

On Thursday afternoon, Kevin McCarthy (R-California), the majority leader in the House of Representatives and the front-runner in the race to succeed John Boehner (R-Ohio) as speaker, shocked Washington and most of his colleagues by abruptly withdrawing as a candidate.

Earlier on Thursday, according to the websites Politico, Salon, Huffington Post and others, Steve Baer, a longtime conservative activist who has lived in Riverside since 1989, sent emails to at least eight Republican lawmakers, including McCarthy, threatening to expose an alleged affair between McCarthy and Renee Ellmers, a Republican congresswoman from North Carolina. The email also reportedly was sent to Ellmers.

The subject line of the email, according to published reports, was “Kevin, why not resign like Bob Livingston?” Livingston was a Republican House member from Louisiana who was about to be elected speaker of the House in 1998 when he withdrew from the race and resigned from after admitting to engaging in an extramarital affair.

According to Salon, “Baer urged McCarthy to spare his family and congressional colleagues the ordeal of the allegations being raised, and suggested that concealing an affair would be a national security risk because of the possibility of extortion.”

Baer did not immediately respond to emails and phone calls Friday afternoon requesting comment about the emails.

In 1990, Baer ran in the Republican primary for Illinois governor, losing to Jim Edgar but receiving about 33 percent of the vote. He has been active in national politics recently, having played a role in galvanizing support for Rick Santorum in Iowa in 2012.

This time around Baer is supporting former Arkansas governor Mike Huckabee for president.

Baer is known for operating behind the scenes and for sending out emails and robocalls. In 2013 the conservative journal National Review published a story about Baer headlined “This Conservative Mega-Donor is the World’s Most Successful E-Mail Harasser.”

Salon described Baer as a “Chicago based GOP donor and known gadfly.”