Arnie would be their best chance, but the Trumptards hate him because he attacked their messiah.
Arnie is the only way they can go -- an actual conservative with ethics. Trump is a radical populist and narcissist who operates 100% from self interest.
The modern Trump voter isn't actually a conservative. You only need to look at policy positions and their actions to see that. The are radicalised populists and Christian neo-fascists.
They mindlessly worship Trump like people worshipped Stalin, Putin, or Hitler. Trump could do anything and they would continue supporting him, including over throwing the government.