I guess you have to look at it from a national perspective. His name can’t appear on the ballot twice in Kentucky, but there is no reason why he can’t just be on the ballot for Senator in KY AND on other states’ primary ballots for the Republican Nomination.
The question is at what point does he decide that he needs to be on the ballot for the KY Republican Primary for President and what his chances of securing the nomination are?
My guess is he’ll delay his inclusion on the KY ballot for Republican Presidential Primary just long enough to shut Grimes up.
His name would have to be on the KY primary ballot for senator, even if unopposed.
I think the deadline for deciding on having his name listed for the presidential Primary is April 1 before the date of the May primary.
If he decided to be listed for President, I would think he would have withdraw from the senatorial race, and that might lead to no Republican nominee for the November election due to the April 1 candidacy filing requirement. Even if there is another way to have a nominee, the outcome would likely be turning over the seat to a Democrat.
He’d be best to stick with the senate. I can’t see him getting the presidential nomination.