Due to Donald Trump’s comments and unpresidential temperament, there is renewed discussion about doing something to deprive Trump the Republican Party nomination. While some will say this is undemocratic and unfair it would be preferable to the constitutional crisis that might ensue if Trump were elected in November.
First, there could be a move to have the electors of the Electoral College pick someone else. The electors were intended to be a buffer between an uninformed electorate and having Congress pick the president. However, this has never been done before. Some states might also try to assign the electors by some method other than the results of the November election; they could be selected by the legislature.
Second, the Congress could refuse to accept the electoral votes or delay the counting of the votes. The Speaker of the House would then become Acting President.
Third, there could be a move to declare that President Trump is under a disability and unable to discharge his duties under the 25th Amendment. This might be seen as a coup by half of the country.
Fourth, there could be a move to impeach Trump. This would also be seen as a coup and trying to overturn the results of the election.
Five choices and none of them are very good.
Sixth choice, elect Hillary Clinton President.