Lately, I've seen a couple articles explaining how Republicans could keep Trump out of the White House without using convention shenanigans. It would have the added bonus of also keeping the Democratic nominee out. The secret lies in a little known provision of the Constitution to throw the election to the House. There are two versions. Both are pretty ridiculous speculation. They involve the Electoral College...
Most people know that the president is not chosen by a popular vote, they're chosen by the Electoral College (fun fact: the phrase "Electoral College" is not in the Constitution). That same most people probably don't think about what that means very often, if ever. When we vote for in November, we are not voting for our preferred presidential candidate. We are voting for a slate of people who promise to vote for that candidate five weeks later in Washington. If no one gets a majority in that election the House of Representatives holds its own election. Each state gets one vote. To get that, the state delegations hold a mini-election. The winner of that vote is the state's vote in the House vote. Got that?
Here's version one, from Huffington Post. Faced with Trump being their candidate, panicking establishment Republicans slap together a third party team that takes enough electoral votes from both sides that neither one has a majority. The election is thrown to the Republican dominated House who elect their chosen third party team. There are several glaring flaws in this clever scheme. In many states, it's already too late to get onto the ballot. More importantly, getting votes is not enough; they need to take entire states to collect electors. In 1992, Ross Perot (remember him?) gained 19 million, votes but didn't win a single state. Even more difficult is the fact that these states have to draw from both sides of the aisle to throw the vote to the House. It's hard to imagine Democratic leaning states to flock to the banner of a hand-picked, Republican establishment team.
Version two is from the Washington Post. This one is not only unlikely, it has the added feature of causing a major constitutional crisis. Article II, Section 1, Clause 2 of the Constitution says: "Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors... [italics mine]." In the early days of the Republic, many states did not allow the voters to choose the electors. The manner they directed was for the legislature to hold a vote for the electoral slates. This was based on the general fear of mob rule held by the upper classes. This is why many states originally only extended the vote to property owners and why Senators were not elected by a popular vote until 1913.
The version two clever scheme is that a bunch of states will change their laws returning the election of electors to the legislatures. The majority of states have Republican legislatures making it possible to steal the election from both Trump and the Democratic candidate. The result would be be multiple constitutional crises at both the federal and state level, endless lawsuits, hundreds of recall elections, and probably violent protests. Changing electoral law in the middle of an election is the worst election idea in the history of bad election ideas.
Basically, if Trump comes to the convention with a majority of the delegates, or even a good plurality, the Republicans have to go with him. Yes, his candidacy is almost guaranteed to be a disaster, but all the alternatives are worse.