“I wonder, if Trump starts a new party will any current elected congress people switch parties immediately?”
IMO, a bad idea. I think Trump’s plan is to continue to control the Repub Party. If he doesn’t get a 2nd term now, he will only be unleashed to regroup.
Trump has never controlled the party - they’ve never supported him from the beginning. The Dems and Repubs are all part of the same deep state junta.
The political system is set up to allow for only two parties. George Wallace ran as an independent in 1968 and Ross Perot did the same in 1992 and 1996. They facilitated the creation of third parties, the American Independent and Reform Parties, respectively. After the founders left the parties, the followup Presidential candidates received a small fraction of the vote in subsequent elections. The parties faded away into oblivion. A party created around Trump would likely suffer a similar fate.