Mitt Romney overwhelmingly won the Republican Senate nomination in Utah, beating back a conservative primary challenge in the contest to succeed retiring GOP Sen. Orrin Hatch.

The primary win makes Mr. Romney, Republicans’ 2012 presidential nominee, the heavy favorite to win the fall general election in deep red Utah. He defeated GOP state Rep. Mike Kennedy, who forced him into a primary election by outpolling Mr. Romney at the party’s April convention—a forum typically dominated by the party’s most-conservative activists.

Mr. Kennedy campaigned raising questions about his rival’s ability to get along with President Donald Trump, citing the harsh criticism Mr. Romney leveled during the 2016 presidential campaign such as calling Mr. Trump a “phony” and a “fraud.”

Mr. Romney has since toned down his criticism of the president, and won Mr. Trump’s endorsement for his Senate bid. Mr. Romney, a Mormon in a majority Mormon state, also served as Governor of Massachusetts, but forged ties with Utah when he ran the 2002 Winter Olympics in Salt Lake City.

Democrats’ Senate nominee is Jenny Wilson, a member of the Salt Lake County Commission who is daughter of Ted Wilson, former mayor of Salt Lake City. But Utah hasn’t had a Democratic senator since 1977; the seat is rated “solid Republican” by the nonpartisan Cook Political Report.