I'm sure I've seen a poll where he approval for Trump had gone up significantly among Republican voters, but I can't lay my hands on it.
So I can't actually read the small print, which matters when dealing with percentages.
Because one possibility is that it's not that more people approve of Trump, but that people who don't approve of him are ceasing to vote Republican.
All of which only matters if democracy holds. If the GOP continues to work with him to undermine democracy, then all bets are off.