It's not over, for Republicans. But you can see over from here.
Trump's sweep in Pennsylvania, Maryland, Connecticut, Rhode Island, and Delaware means he needs just about half of remaining delegates to win the nomination. Before Tuesday's results came in, Trump needed 59 percent.
That leaves Indiana as the next major hope for the Republican Party's anti-Trump not-coalition, and it's a thin one indeed. Ted Cruz, like John Kasich, has been mathematically eliminated from contention, and both are now staying in the race solely as an effort to deny Trump the full 1,237 delegates needed to win nomination on the first ballot. Then, the theory goes, the sensible wags of the Republican Party will get together and nominate someone more palatable to the public. Ted Cruz believes that person should be Ted Cruz. John Kasich believes that person should be John Kasich. None of those unpleasant people are in charge of whether that happens, however. That task lies with the delegates themselves.
According to exit polls, the leading candidate going into the convention should be the nominee—by margins of 70 percent in Pennsylvania, 66 percent in Maryland, and 68 percent in Connecticut.
Nevertheless, the theory is that if Cruz can do well enough in Indiana and the other remaining states to leave walking internet comment thread Donald Trump with only 1,236 pledged delegates going into the convention, surely all the remaining delegates will come to their senses and agree to nominate someone, anyone else. Because if there's one thing the Republican Party has been known for, these last two decades, it's "coming to their senses."
So you can see the end from here. The thought of somehow replacing the unacceptably ridiculous Donald Trump with someone like, say, the unacceptably ridiculous Ted Cruz is all but over. The coalition of teeth-grinding pundits terribly, terribly peeved that a loudmouthed xenophobic blusterer has taken over a party primed by years of punditry to see loudmouthed xenophobic blustering as being the highest and best use of political power is over. The Republican Party as crafter of doctrine, as opposed to eggshell-thin wrapper around raw racism and donor-driven tax cuts, is over.
One of two things will now happen. The first: All the pundits and politicians who previously declared Donald Trump and his non-policies to be stains on the republic will in the next few months have a remarkable change of heart, suddenly declaring that with the White House on the line, well, maybe Donald Trump is actually a fine and reasonable man. Or two, all hell will break loose as those same party elders abandon the Trump candidacy, condemn Trump's many, many Republican voters as not-true-Republicans, and go off to pout in their own tiny ideological fortress for the duration of the campaign season.
It's likely to be the first. I don't think any of us can reasonably suppose that either the Bill Kristols or the Mitch McConnells of the party have ideological stances so deeply felt that they would risk losing even a wee bit of power by standing up to them; already you can see party elders, who used to call Donald Trump's rabid anti-Muslim stances "unhinged" and "idiotic," quietly acquiescing to that same stance now. No doubt by October Trump's demands to close down the borders to Muslims and deport every undocumented immigrant in the nation in one fell swoop will be outright praised in op-ed columns by the very same voices that currently are grumbling about the need for a third party to stop all this nonsense.
But as for the specific fantasy of stopping Trump through any means other than a convention floor riot? That part is done. It's party acceptance or party war, now. Those are the only two options.