TALLAHASSEE, Fla. (AP) — Republican U.S. Rep. Ron DeSantis resigned from Congress on Monday to focus on his bid to become Florida’s next governor.

DeSantis sent a letter to House Speaker Paul Ryan and asked that his resignation be retroactive to Sept. 1 so he receives no pay for the month. The northeast Florida congressman won the Republican nomination on Aug. 28 with the help of President Donald Trump’s endorsement. Early polls show he is in a tight race with Democratic nominee and Tallahassee Mayor Andrew Gillum.

“As the Republican nominee for Governor of Florida, it is clear to me that I will likely miss the vast majority of our remaining session days for this Congress. Under these circumstances, it would be inappropriate for me to accept a salary,” DeSantis wrote.

The resignation also comes as The Washington Post reports on speeches DeSantis made at an annual event organized by the David Horowitz Freedom Center. Horowitz is known for anti-Muslim rhetoric, and the Southern Poverty Law Center says he has been a driving force behind anti-Muslim, anti-immigrant and anti-black movements. Other Republican congressmen, U.S. senators and governors have spoken at events organized by Horowitz, including U.S. Attorney General Jeff Sessions when he was still in the Senate and then-Texas Gov. Rick Perry.

Former Pinellas County Republican Chairman Tony DiMatteo said DeSantis’ association with Horowitz’s group wouldn’t make a difference in the election.

“As far as being associated with a very conservative group? He’s very conservative,” DiMatteo said. “DeSantis is fine.”

Still, race has already become an issue in the campaign, with Democrats and Gillum criticizing DeSantis for his choice of words when he said Florida voters shouldn’t “monkey this up” by electing Gillum, who hopes to become Florida’s first black governor.

Gillum upset several other Democratic nominees in the primary and has garnered national attention since then. In the immediate aftermath, he has raised more money than DeSantis.

Republican businessman Michael Walz faces Democrat Nancy Soderberg in the race to fill DeSantis’ seat. Soderberg is a former United Nations ambassador and served on President Bill Clinton’s National Security Council.