It's endless. It never stops.
The dominant Republican ethic is immoral in every place it can be if one assumes American values (democracy, egalitarianism, church-state separation, tolerance, and the rule of law) and that the purpose of government is that which is outlined in the Constitution's Preamble. The party's only principles seem to be to acquire, consolidate, and retain power at any cost to serve wealthy interests whatever the cost to mankind or the environment.
Trump is not the Republican party.
No, he's not. There's also Graham, Cruz, Hawley, Johnson, Cotton, Scott, McConnell, Paul, McCarthy, Jordan, Clyde, Gosar, Gohmert, Gaetz, Boebert, Greene, Abbott, DeSantis, Noem, and Kemp. And tens of millions of people that vote for them.
But consider why Trump is weaker, which could be due to getting fed up with his immorality, eg, the insurrection. This would contra-indicate moral collapse.
We know why the Republicans are abandoning Trump, and it's not due to finding Trump immoral. One can rule out the insurrection being a problem to them by looking at history. They objected to Trump being impeached for it and rallied to prevent conviction. Although the likes of McConnell, McCarthy, and Graham initially spoke against insurrection, withing days they were back to licking Trump's boot. The Senate Republicans refused to cooperate to form a bipartisan committee to look into January 6th, and the House did everything in its power to prevent and then discredit an analogous select committee.
Trump's crime was costing them the White House, both houses of Congress (the Senate twice), and most recently, their failed red wave. As soon as they saw that he's now toothless, they bailed on him. Look at Pence's behavior. We see him becoming progressively less silent about Trump in just the last few weeks.