In a YouGov poll conducted between July 25-29, 59 percent of Republicans surveyed said they would prefer a president under the age of 75. Trump celebrated his 78th birthday in June. Forty percent said they had no preference, and just two percent said they would prefer a president over the age of 75.
Where they made their VP announcement, clearly without an iota of audience testing.
But nothing really stops Trump from withdrawing and ceding the nomination to his VP. Or dying, for that matter.
I suspect that’s more just because Biden would have been easier to beat and they’re sore over not being able to coast to victory.