Trump had good reason to question the election results since based on exit polls he probably won; the correct response is that the exit polls didn’t take into account that Democrats were more likely to use absentee ballots (usually absentee and normal voting yield similar results). Trump also ignore the Republicans did well in most races, and “ballot box stuffers” never split tickets. But to say that Trump has no basis to suspect fraud is totally wrong.
In foreign affairs, Trump’s populists and Biden’s progressives all tend to be isolationist. Trump initiated the policy that Biden implemented. For obvious reasons, Biden doesn’t want to take credit for Trump’s foreign affairs policy (even though Biden has no problem claiming credit for Trump’s Covid-19 vaccines. By the standards of 1980, Trump is a RINO (and back then, he was Democrat). Expect a conservative running on platform of fiscal responsibility and a strong foreign policy to try to re-take the Republican party, and return to the policies of Ronald Reagan’s administration.