A serious threat, or an attempt to remind people of anti-establishment bona fides? Ben Carson’s threat began with a report in the Washington Post that the Republican Party has begun to plan for a brokered convention, especially for the contingency of Donald Trump getting a plurality of delegates but remaining short of a nomination on the first ballot. Robert Costa and Tom Hamburger give a picture of what a smoke-filled room might look like, if people were still allowed to smoke inside buildings:

More than 20 of them convened Monday near the Capitol for a dinner held by Republican National Committee Chairman Reince Priebus, and the prospect of Trump nearing next year’s nominating convention in Cleveland with a significant number of delegates dominated the discussion, according to five people familiar with the meeting.

Weighing in on that scenario as Priebus and Senate Majority Leader Mitch McConnell (R-Ky.) listened, several longtime Republican power brokers argued that if the controversial billionaire storms through the primaries, the party’s establishment must lay the groundwork for a floor fight in which the GOP’s mainstream wing could coalesce around an alternative, the people said.

However, Costa and Hamburger also point out that both Priebus and McConnell didn’t push for an anti-Trump strategy either:

Because of the sensitivity of the topic — and because they are wary of saying something that, if leaked, would provoke Trump to bolt the party and mount an independent bid — Priebus and McConnell were mostly quiet during the back-and-forth. They did not signal support for an overt anti-Trump effort.

But near the end, McConnell and Priebus acknowledged to the group that a deadlocked convention is something the party should prepare for, both institutionally within the RNC and politically at all levels in the coming months.

That seems like a pretty good idea, at least so far in this cycle. Usually the primaries come down to one or two serious contenders for a nomination, but clearly we will head into Iowa and New Hampshire with four or possibly five serious contenders, plus the cash still left in Jeb Bush’s super-PAC. The RNC has to prepare itself for a floor fight for the nomination in July 2016; after all, it’s still their convention, and delegates operate under the RNC’s rules as well as the rules of their state parties. If the RNC didn’t start thinking about how best to operate in that context now, one could easily accuse them of incompetence rather than throwing the game. As long as the process remains transparent and fair to all contenders — and can demonstrate that impartiality — there should be no objection.

Perhaps that’s what Carson wants to underscore with this threat:

The retired neurosurgeon lashed out Friday morning at reports of a recent closed-door meeting of Republican establishment leaders focused on deep divisions within the GOP electorate, particularly the continued strength of billionaire businessman Donald Trump. The Washington Post reported that the group, including Republican National Committee chairman Reince Priebus and Senate Majority Leader Mitch McConnell, discussed the possibility of a “brokered national convention” if there isn’t a clear winner in the party’s months long primary election season.

“If this was the beginning of a plan to subvert the will of the voters and replace it with the will of the political elite, I assure you Donald Trump will not be the only one leaving the party,” Carson said in a statement that referenced Trump’s repeated threats to leave the GOP if treated “unfairly.”

“I pray that the report in the Post this morning was incorrect,” Carson added. “If it is correct, every voter who is standing for change must know they are being betrayed. I won’t stand for it.”

While this isn’t exactly an empty threat, it’s not the kind of game-changer that a Trump defection might be. Carson has been steadily losing ground in the GOP race, although certainly still in the top tier. His numbers in the RCP polling average over the last month show a steady decline:

That’s a fade, not a collapse, but it’s accelerating in the latter period, and he’s now edging into a position behind Ted Cruz and Marco Rubio. Furthermore, Carson doesn’t have the celebrity following of Donald Trump, nor his current political affinity. Carson gets the most personally favorable ratings in the GOP’s contingent, but Trump gets the worst and he’s still running away with the polls. Plus, Trump has almost unlimited funds for an independent run, where Carson would have to fundraise outside the party structure that is more interested in electing a Republican (and probably in preventing Trump to get to the nomination), so Carson can’t expect to get much traction outside the GOP. Without a great deal of personal wealth — on a Trumpian or Perotesque level — independent runs have very little chance of viability.

Trump has already made noises about running as an independent, explicitly citing a poll that stated that 68% of his current supporters would go with him if he left the GOP. There are plenty of reasons to consider this an empty threat, too, including filing deadlines that I left unmentioned that would require Trump to start organizing in the next few weeks if he plans to exercise that option. The Washington Post points out another reason, which is that only half of the polling Trump gets is firmly committed to him. That’s still better than Trump’s opponents, but points out a serious limitation on Trump’s options:

What is surprising is this, buried in the Times’ report on the new survey: About a third of the people who’ve picked a candidates say their minds are made up. But among Trump supporters, that figure rises to more than half. Among all of Trump’s opponents, that core support is only one-quarter.

That puts the number of firm Trump voters at around 15%. If the field narrows from its current numbers, say down to two or three other options than Trump, that might be enough for Trump’s plurality to fall below a different consensus candidate. The brokered convention might not materialize if enough candidates get out of the way for those with realistic chances to beat Trump for the nomination. Rather than worry about RNC plans to manage a floor fight for the nomination, the real danger for both Trump and Carson is that the RNC’s donor base might finally get fed up and start to unify behind one or two candidates, and convince the others to push for Cabinet appointments or a VP slot instead.