I'm surprised that people have already forgotten the 2016 US presidential campaign.

Donald Trump did not become president because of the Republican party. He became president in spite of the Republican party. In fact, he nearly destroyed the national Republican party in the process. The Republican party has not changed, and there is no reason to expect Trump to be much help for Republican candidates, because the people who put Trump in the White House don't necessarily like Republicans.

In Virginia, in the days before the election, Democrat Ralph Northam was going easy on Trump, running a TV commercial with the message that he would work with Trump where he agreed with him and oppose Trump where he did not agree with him. That suggests a view that Northam saw Trump as continuing to be popular enough in Virginia that Northam didn't want to alienate Trump voters, and that may explain why Northam did better against Gillespie than Clinton did against Trump in Virginia.