Remember that only 75% of Republicans approved of George W. Bush’s performance in the final Gallup poll during the closing days of his administration in early 2009. This goes to show how strongly Trump’s grip on the Republican Party still is right now.
But Dubya quickly lost his grap after he left office. The Tea Party wave of 2010 was also a clear rejection of his policies and legacy and many Bush era establishment officials were swept out of office in primaries. Of course, it was not for the better.
What happens this time remains to be seen, but Republicans may actually be in a lose-lose situation now. Continuing to embrace Trumpism may not get them anywhere, especially with Trump himself not on the ballot. Going back to establishment conservatism, free trade and neoconservatism would lose them a ton of voters Trump appealed to while former, more moderate Republicans are gone.