Except he did.
When President Trump picked Harriet Hageman, she had no resources and was an underdog to the incumbent Liz Cheney,
Hageman went on to CRUSH Liz Cheney by a massive close to 40% with President Trump's support.
Trump would have endorsed Idi Amin if he was running against one of the 10. The majority of his wins are not changes to the base of the party. Bringing the swamp back does little to a movement. If he brought 180 new bodies into DC to replace the swamp.....that would be the greatest show on earth. Keeping the swamp helps the same leadership and committee assignments and the same uniparty into a new session.
I still view him as one of our greatest presidents...if not the best. If he makes it back, he is an instant one term president again and the swamp and their unlimited monies can wait him out. If people want to change the party, start with your school boards, local GOP County party, township offices, county commissions, and up the chain. If you control the base you can effectuate change.