They never liked him. A few are genuinely concerned about the profound threat to constitutional order. And they have their boy, Mike Pence, waiting in the wings.

All in all, Republicans are slowly but surely contemplating the politics and mechanics of ridding themselves of President Trump.

Some Republicans have the advantage of principled concerns about Trump. Others will see their problem in purely political terms, given the strength of Trump Republican voters. All will be looking for the easiest way out. And all would vastly prefer President Pence.

The Republican establishment is already there. Mike Pence is everything they could hope for. Supply-side tax cuts, anti-gay, anti-abortion, anti-Obamacare, military muscle-up, it’s the full package. They’re in the “when and how” stage already.

“When and How” are the big questions. Strangely, the legal reasons for impeachment or removal are somewhat secondary. The lessons of the Nixon and Clinton impeachments are obvious. You don’t get to the merits of impeachment until late in the game.

First, a popular president is unimpeachable, no matter what the reason. As long as Nixon was riding his re-election wave, notions of impeachment were nonsensical. They remained so until he defied the courts. Even then his was a slow-motion fall. Clinton, caught red-handed in lies, was never in serious trouble, beyond the ideologues in the House. His popularity actually increased during the impeachment hoo-hah.

Second, party loyalty is a bar to impeachment. As long as Congressional Democrats stayed with Clinton he was fine. As soon as Congressional Republicans turned, Nixon was toast.

What does this mean for Trump? It gets complicated. Trump has the genuine support of only a handful of Congressional or Establishment Republicans. The bulk of senators and Congress members tolerate him. That would indicate erosion potential. But not as simple as it seems. In almost every Congressional district and every state, rank and file Trump Republicans control nominations. It seems that nothing Trump does can dislodge them from standing by their man. Even if Trump falls, there will be blood in the streets come Republican primary time.

Events tend to resolve these kind of contradictions. No one knows what will hit next. But there are things to watch for. Keep an eye on the polls. Then watch key senators. McCain and Graham will move first, Snow, Flake, Sasse and others won’t be far behind. Others are more careful. Watch Grassley, Cassidy and Kennedy. Ultimately Orrin Hatch will be decisive.

Among House Members, group-think and discipline are more pervasive. They won’t be opinion leaders, and ultimately will be late to the party. But Republicans are moving in the direction of solving the nation’s Trump problem and installing Mike Pence even now.

Two additional things to remember.

Impeachment is not the only avenue for removal. The 25th Amendment provides for removal for incapacitated presidents. Guess who triggers such a removal process? Mike Pence.

This is not a cause for rejoicing, even for folks like me who see Trump as a profound threat to the nation. We are in trouble.