Here I am again trying to be a political fortune teller. I was wrong in assessing that Americans were smart enough to decisively toss out Mr. Trump on Nov 3. That was not the case: Mr. Trump was still a viable condender.
If Republicans do split, the "normal" wing will have to accept the fact that Democrats will have a much easier path to electoral victory. Even a 20% splinter should achieve this result. So the "normals" are actually making a very big decision: should the Democrats or should the extreme elements of the Republican Party be running the country? It will probably take two electorarl cycles to fix this problem. So which is worse from their perspective: the Democrats or the Trumplicans?
While the normal Republicans are pondering this split, they also need to figure out the internal structure of their new Party. In "How Democracies DIe," Livitsy and Zilblatt contend that the primary system for the internal party election played a big part in the election of Mr. Trump, who was both an outsider to the Party and a candidate unfavorable to the higher echelons. In other words, the long-serving Republicans really did not have a brake on a populist like Mr. Trump. A tiered election (like the Founding Fathers had created) could do a lot to put on this brake. But Amerlicans prefer direct elections, thus making membership less attractive.
Circa 1987, Canada's Progressive Conservative Party effectively split into two: a splinter called the Reform Party became a serious condender in 1988 AND by 1993 surpossed the Progressive Conservative in vote and elected MPs. But with the two parties reaching out to the conservative base, the LIberal Party won the election for governing party. It was not until 2005 that the conservatives united politically and could wrest control from the LIberals. A process of almost 20 years! Splitting of a political party has consequences.
Link to my review of "How Democracies DIe"