According to Rolling Stones, 55% of Americans support the possibility of an impeachment of Donald Trump. If this situation is confirmed by other polls, the choices of Republicans in Congress will change.
For Republicans whose mandate will be renewed at the same time as the presidential election, the immediate trade-off is whether it is better to oppose impeachment or promote his own reelection that would go through support for impeachment.
The tipping process can go very fast and the analysis that an impeachment could not take place because of the Republican majority in Congress can quickly become obsolete. The future is not written.