PROVO, Utah (AP) — U.S. Rep. John Curtis will succeed Mitt Romney in the U.S. Senate after the Republican won a victory over his Democratic opponent in deep-red Utah.

Curtis defeated Democrat Caroline Gleich, a mountaineer and environmental activist from Park City, in a race that was often pitted against each candidate Climate policy. The new senator leads the Conservative Climate Caucus on Capitol Hill and has developed a reputation for pushing back against party leaders like Donald Trump who falsely claim that climate change is a hoax.

The former mayor of Provo began his political career as a county Democratic Party official. He is the longest-serving member of the US House of Representatives delegation in Utah and is considered a moderate in the spirit of Romney.

Curtis, 64, said he plans to develop his own brand of conservatism in the post-Romney era of Utah politics, with an emphasis on bringing Republicans to the table on climate change issues.

His group takes a market-based approach to climate issues, countering Democratic policies with proposals that Curtis says are aimed at reducing emissions without endangering American jobs and economic principles. Gleich had accused him of pandering to the fossil fuel industry instead of supporting measures they say are necessary to protect public lands, air and water.

Curtis had a long shot at winning in a state that hadn't elected a Democrat to the Senate since 1970.

In the June primary election, he emerged from a crowded pool of candidates Defeat a Trump-endorsed mayor.

Moderate Republicans tend to prevail in statewide elections in Utah. Members of The Church of Jesus Christ of Latter-day Saints, who make up about half of the state's 3.4 million residents, have been a reliable Republican voting bloc for decades. But many were hesitant to embrace Trump and his allies, saying the former president's brash style and comments about immigrants and refugees contradicted their religious beliefs.