Donald Trump did not amass a majority of delegates on Super Tuesday. But he could soon.

If the people in the rest of the nation vote as the Super Tuesday results suggest they would, Mr. Trump would easily amass a majority of delegates and avoid the contested convention that his opponents hope to force and win.

He could even do so without wins in Ohio and Florida, the two largest winner-take-all states, where he faces opponents in their home states.

Mr. Trump would amass so many delegates because the rules become more biased toward candidates who win, allowing him the chance to take an overwhelming share of delegates with just a minority of the vote. It becomes easy to win lopsided delegate margins starting March 15, when states are allowed to apportion their delegates on a winner-take-all basis. At the same time, the primary calendar doesn’t become less favorable and may even become more advantageous to him, depending on which candidates stay in the race.

But the results so far also indicate he could still be defeated, suggesting Mr. Trump is far from winning a majority of the popular vote. He could be denied a majority of delegates if the field narrowed to Mr. Rubio.