(CNN) Mitt Romney declared his bid for the US Senate from Utah on Friday. Despite being a fellow Republican, Romney is expected to be a thorn in President Donald Trump's side. Romney refused to endorse Trump during the 2016 campaign and, although he didn't reference the President by name, Romney made it clear with a number of references (such as to immigration) in his campaign announcement that he comes from a different wing of the Republican Party than Trump.

Romney couldn't have chosen a better state to be an anti-Trump Republican than Utah.

Utah was one of Trump's worst state performances during the 2016 primary season. Trump garnered just 14% of the vote and finished in third place behind Ted Cruz and John Kasich. Along with Minnesota, it was the only state where delegates were assigned in a caucus or primary (not a convention) in which Trump finished below second place. In no other state did Trump garner less than 20% of the vote.

Republican dislike of Trump in the state translated to the general election. In the 28 states with an exit poll , Trump's performance among Utah Republicans was by far the worst among Republicans.

He won a relatively low 64% of Utah Republicans . In the average state, Trump won 88% of Republicans. Besides Utah, he never won less than 84% of Republican voters. And don't forget that Evan McMullin's longshot independent bid for President in 2016 was largely centered on Utah.

Of course, it's not just the fact that Utah Republicans aren't the biggest fans of Trump that makes the state friendly territory for Romney. It's that Utah is heavily Republican. Over the course of 2017, Republicans and independents who lean Republican made up 57% of Utah adults in Gallup polling . Democrats and independents who lean Democratic made up only 29% of Utah adults. That 27 percentage point Republican lead was just behind Wyoming and North Dakota for the most Republican states in the nation.

Romney's path becomes clear when you realize the disparity between how Republican Utah is and how it feels about Trump. When you compare Trump's net approval rating (approval rating minus disapproval rating) with the Republican margin in party identification, Trump is really underperforming.

Trump had a net approval rating of just +1 percentage point in Utah during 2017, according to Gallup . That's a 26 percentage point difference with the Republican party identification edge. And while Trump tended to underperform the party identification in most states, he averaged just a 9-point difference. The 26-point gap in Utah was the largest of any state.

The bottom line is that Romney is running in the perfect state to be a anti-Trump Republican. He's in a strong position to take advantage of the the fact that 39% of Utah voters held an unfavorable view of both Hillary Clinton and Trump in 2016. No other state came anywhere close to as many people disliking both of them.

CORRECTION: This story has been updated to note that Utah is behind only Wyoming and North Dakota as the most heavily Republican states.