Donald Trump speaks at a rally Tuesday at Briar Woods High School in Ashburn, Va. (JIM LO SCALZO/European Pressphoto Agency)

Prominent Republicans have just joined Zune owners and the front office of any team that ever signed Tim Tebow in having a bad case of buyer’s remorse.

After Donald Trump’s spectacularly bad week — beginning with the final night of the Democratic convention, rolling past slumping poll numbers and continuing into new reports of a campaign in turmoil — there's an audible current of mumbled what-ifs among party leaders. What if a Zeusian thunderbolt from the sky were to suddenly vacate the head of the Republican ticket? What might happen then? What if what if what if?

This is purely aspirational, for three reasons.

The first is that there is no mechanism for removing a nominee from the ticket. It makes sense that this wouldn’t be written into the rules; after all, what are the odds that between the nomination and the election the party would so drastically change its mind on its candidate?

After a bad week for Republican presidential candidate Donald Trump, some in the Republican Party are reaching new levels of panic. Here's why picking a new nominee might not be the answer. (Sarah Parnass/The Washington Post)

Few people know the party’s rules as intimately as Josh Putnam, lecturer at the University of Georgia and the guy behind the invaluable site Frontloading HQ. He explained by email why the party was stuck with Trump.

There is a rule, Rule 9, which spells out how a nominee can be replaced. But: “The rule is pretty clear about the conditions for filling a vacancy,” Putnam writes. “The list is short: death, declination or otherwise. And let’s be clear here: The rule is intended to fill vacancies, not to lay the groundwork for a replacement.

“Some have speculated that ‘otherwise’ is ambiguous. Taken out of context it is,” he continued. “However, under the provisions for filling vacancies, it clearly fills in any gap between death and declination (i.e.: an incapacitating illness, but one that leaves the nominee neither dead nor able to decline to run further). And that was the intention.” In other words, the only way Trump won't be the nominee is if he drops dead, falls into a coma or simply decides not to run.

It’s not clear which of those is least likely. Probably the coma, just given the odds. There’s absolutely no indication that Trump plans to drop out, and the nature of his candidacy and the moment is such that he’s unlikely to see any massive drop in his core base of support. He’s raising money and having fun being the center of attention. Oh, and he also hasn’t shown any concern about the long-term success of the Republican Party, as he demonstrated on Tuesday when he declined to endorse the reelection of House Speaker Paul Ryan.

It’s possible that the party could amend the rule, Putnam notes. “There have only been two instances in which the convention allowed — under rule — rules changes outside the convention,” he wrote. That said, the party spent the weeks leading up to and including their convention making clear that they had a unified front and wouldn’t change the rules to stymie Trump. “A majority of the committee would have to pass any change and then three-quarters of the full 168 member RNC would have to vote in favor of it for any change to be adopted,” Putnam explains. “That’s a high bar in uncertain times.”

Changing the rule would raise another problem: backlash. If the party were to suddenly try to oust Trump, they would have the same rebellion in their base that was threatened when the talk was of a contested convention. Trump’s fervent supporters, the core that seems unlikely to bail on him no matter what, would be very unlikely to accept a rules change that swapped Trump for someone like, say, Mitt Romney. Meaning that the Republicans wouldn’t really be improving their chances for victory in November — and would probably do more long-term damage to the party.

A third problem for replacing Trump is that states have guidelines on when and how people can be removed from the ballot. As The Post’s Paul Kane noted on Twitter, we’ve seen scenarios in the past where candidates have died before the election but were still listed on the ballot because the deadline for removal had passed. In Missouri in 2000, Mel Carnahan died in a plane crash before the election, but after the deadline for getting his name off the ballot. He won, and his wife took his seat.

Changing the party’s rules to oust Trump is not the sort of thing that's going to happen today, if it were to happen at all — and the clock is ticking.

So that’s that. Donald Trump is your Republican nominee for president and he will almost certainly be the Republican nominee for president on Nov. 8. Unlike with a Zune or a Tebow, there’s no eBay and no Eagles to let the party push the problem to someone else. As with an eBay auction, the moment to keep Trump from being the nominee was right before you clicked “Buy It Now.”