Are there any top Republican leaders left? In what way are they leading?
There was a "Never Trump" movement of Republican leaders. It's dead.[1] By now, most of the Never Trumpers are either out of power or have groveled to Trump. The National Review, a conservative publication, wrote: "At no point did Never Trump possess the basic traits of a political movement: a small number of leaders and large number of followers." It was all leaders, or former leaders, or people who thought they should be leaders. The article says Never Trump was composed of "1) experts in foreign policy, economics, and law ... 2) campaign professionals ... and 3) public intellectuals ..." Not Republican governors and members of Congress. Not big donors. Those people only matter when they're in power. There are small conservative journals in which they still write. Few read them. They're not on Fox News.
It's not at all clear what the GOP looks like after Trump. The most likely Republican successors are said to be Vance, Rubio, and DeSantis. The last two have failed badly at presidential bids before.
[1] https://www.nationalreview.com/corner/the-end-of-never-trump...
I wonder how many will simply become "Trump Republicans" and follow some other leader when he's gone? Or will some simply pretend to wake up and have realized they had Trump Derangement Syndrome the whole time and are ready to come back to reality?
No. You can see this on what happened to a recent bill for a drinking water project in Colorado.
It was so uncontroversial that it passed the House by unanimous consent. That doesn't mean 100% were for it, but it means any who were not didn't think it was worth making even a token effort to stop it.
In the Senate they passed it on a voice vote, which is what they use for routine and completely non-controversial bills. They are all asked to say yea or nay, and the presiding officer calls it for whichever they think they heard the most of and if no one objects that they misheard it passes.
Trump vetoed it. The official reason given was some bullshit about costs, but no one believes that. The leading theories are that it is because it is important to Lauren Boebert's district and because Colorado won't release Tina Peters from prison.
Boebert upset Trump by being one of the Republican House votes to force the release of the Epstein files.
Tina Peters was an election official who did various illegal and shady things [1] that Trump approves of.
The House failed to override the veto. They are so afraid of angering Trump that they couldn't get 1/3 of Republican House members to to go against Trump on something that they themselves had just recently found completely uncontroversial.
[1] https://en.wikipedia.org/wiki/Tina_Peters_(politician)