Former President Donald J. Trump has driven all of his major primary rivals out of the race. And yet, the voting will go on. Why?

For the most part, the answer is a simple one: It’s just too late for state parties to cancel elections that are already on the books.

“It would be unusual for states to come out and say, ‘Yeah, we’re not going to have a primary after all,’ at this point,” said Josh Putnam, a former political strategist who studies delegate allocation processes. “I would be shocked.”

The deadline for the state parties to submit their plan for the 2024 cycle was back in October, and the Republican National Committee’s rules prohibit states from making any major changes after the deadline.

Strictly speaking, the Republican Party is not bound by law to adhere to its current primary calendar. Could the R.N.C. choose to modify its own rules? Sure. It’s unlikely, though.

Changing things now would be a major shake-up involving a lot of stakeholders: the national party, state parties and state governments, which administer and pay for primary elections, according to Daniel Schlozman, a political scientist who studies parties and electoral rules.