It’s still fairly unpredictable when President Trump will decide to jump into a competitive Republican primary.

But when he does, for the most part, he’s made safe bets: endorsing a Republican congresswoman in Alabama who was likely to win her runoff; attacking GOP congressman Mark Sanford hours before polls closed when he already was in trouble. Even when Trump endorsed the less-establishment candidate last month in Georgia's governor's primary, he did it as polls showed that candidate, Brian Kemp, surging in popularity over the lieutenant governor.

But on Monday, Trump did something riskier. He endorsed Kansas Secretary of State Kris Kobach in Tuesday's gubernatorial primary, despite the fact that some Republicans don’t see evidence that Kobach is going to win the primary over the current governor, Jeff Colyer.

In fact, some Republicans don't think Kobach should win. If Kobach is the nominee, Washington Republicans closely watching the race say, they’ll have to spend a lot of time and money to keep the governor's mansion red.

“If Jeff Colyer is the nominee, Republicans are in good shape to hold on to the seat this fall,” said one Republican insider frustrated by Trump's endorsement of Kobach who spoke on the condition of anonymity to talk candidly. “And if Kobach is the nominee, Republicans face an uphill battle.”

That was code for: Why, oh, why, did you have to endorse Kobach, Mr. President?

Kobach is perhaps best known nationally and in Kansas as the voter fraud guy. Voter ID laws are quite popular in Republican states, but Kobach took it to a whole new level.

He helped lead Trump’s voter fraud commission, which crashed and burned less than a year into its existence without finding evidence of Trump's conspiratorial claim that millions of people voted illegally in the presidential election. Nearly every other secretary of state, Republican or Democratic, refused to hand over all the voter information Kobach's panel wanted, including Social Security numbers, birthdays and addresses.

This week, a federal judge ordered Kobach to pay more than $26,000, citing his “contemptuous behavior” in a voting rights case in Kansas, where she also accused him of failing to send voting rights cards to people who don't show proof of citizenship.

Some Republican operatives think all the voter ID drama left Republican voters with a dislike for Kobach, marking him as someone willing to spin a factually dubious project to become a national figure.

That means that despite his ties to Trump, Kobach is at risk of coming across as too politician-y — a label that has dragged down other Republican candidates this primary season.

Some private Republican polling suggests he's very unpopular, with more than twice as many Republican voters disapproving of him as approving. (Other public polls show Kobach with a slightly higher approval rating, with voters split on whether they like him.)

Polls between Colyer and Kobach show that the race is a nail-biter.

Meanwhile, Republicans worry that either top Democrat who wins Tuesday’s primary, state Sen. Laura Kelly or former Wichita mayor Carl Brewer, could seize the ground that a Kobach nomination would open up with independent and Republican-leaning voters.

Sam Brownback (R), who was Kansas's governor until Trump tapped him for his administration, is incredibly unpopular in the state.

Brownback's unpopularity means the Kansas governor's race always had the potential to be competitive for Democrats. But some Republicans worry that Kobach winning the nomination could make November's race really competitive.

That's the last thing they need in 2018. Republicans hold 33 governor's mansions, near a historic high. At least 15 are competitive this cycle, compared with just six likely competitive seats that Democrats hold.

This isn't just a fight for one race. Any governor's seat Democrats can win back is critical for the future of the party. Many of the governors will be able to veto electoral maps drawn by state legislatures with new census data in 2021. For Democrats, having a hand in the pot in a sharply Republican-controlled state like Kansas would be a bonus.

So is Trump going to lose Kansas for Republicans because he endorsed Kobach? A lot of things have to go wrong for Republicans for that to become a reality.

But one of the first things that some GOP election insiders feared — a Trump endorsement of the candidate they don’t want to win — just happened. Which means Trump has a lot to prove in this endorsement in a way he hasn't had to before.