Maybe, but recall McCain’s betrayal of the conservatives are all POST 2000 -— and also recall that Thompson became notably more conservative as time went on.
Two friends on opposite paths, so to speak.
The Thompson of today endorsing the McCain of today? Possible, but doubtful.
McCain betrayed no one, just because he does not agree with everyting in a conservative plat form does not make him less of a candidate to me that any demorat running.
Romney is surely no fiscal conservative.