How Tuesday stopped the Stop Trump movement

Trump, Clinton add to delegate count

The Stop Trump movement just got stopped.

Facing the slimmed-down field that his critics said would bring him down, Donald Trump routed Ted Cruz and John Kasich in all five Eastern states holding primaries Tuesday. Trump foes have long insisted the bombastic billionaire has a "ceiling" over his Republican support of 40 percent or less.

Instead, Trump easily cleared the 50 percent mark in Maryland, Pennsylvania and Connecticut. He topped 60 percent in Rhode Island and Delaware. On the heels of his landslide in New York last week, it's little wonder Trump declared himself the presumptive Republican nominee.

Donald Trump
Steve Sands | WireImage | Getty Images

He still has political work to do. He hasn't yet won the 1,237 delegates he needs to secure a first-ballot nomination at the Republican convention in Cleveland this summer.

But odds are growing that he will get them by the time California concludes the primary season on June 7 — or if not, end up close enough to become unstoppable.

Cruz hopes for a last stand next week in the Indiana primary and Kasich in Oregon and New Mexico after that. But Tuesday's voting made the alliance they declared this week look feeble.

Bernie Sanders is in no better shape on the Democratic side. Like Trump, front-runner Hillary Clinton hasn't yet won enough delegates for a convention majority. But her victories in four of the five states voting Tuesday pulled her very close.

Donald Trump and Hillary Clinton
Trump and Clinton: It's time

Sanders won only Rhode Island, with 55 percent of the vote. His problem, given the way Democrats award delegates proportionally, is that he needs victories larger than that in every remaining contest to overcome the delegate lead Clinton has accumulated.

The main question now is when, and how, the Clinton and Sanders camps can come together to form the united front for the general election that both say they are determined to create. And it is increasingly likely that united front will be, despite the misgivings of the Republican establishment, against Trump.

Trump, however, has something else in mind: He's urging Sanders to run as a third-party candidate.