The American left and right have always agreed on the role of the individual voter in the government, and the role of the government generally. They only vary on who they think should be allowed to have rights, and the rights they should have. They generally agree on economics, business, the police, and the military industrial complex. Each of which contribute to the general oppression of the non-rich citizens.
Taking one vote from another candidate is worth two votes from someone who is not voting, or who is voting for a non-viable third party.
I know plenty of people who wanted to vote for Kennedy but will probably vote for Trump now that he’s out. This group is likely to listen to former Reagan staffers and republican presidents that they liked.