Donald Trump’s probably unconstitutional proposal to ban Muslims from entering the United States was soon denounced by … exactly who you might expect to denounce it. The three remaining Democratic candidates immediately condemned it. So did several Republican candidates — Jeb Bush, Chris Christie, John Kasich, Lindsey Graham — who are running in the New Hampshire “lane” of the GOP primary, hoping to cultivate more moderate voters.

The more conservative Republican candidates were slower on the draw. Marco Rubio waited three hours before saying (on Twitter) that he disagreed with Trump. Ted Cruz’s and Ben Carson’s campaigns clarified their candidates’ positions rather than saying much about Trump’s. Mike Huckabee, as of early Tuesday, still hadn’t commented.

It’s not obvious what Republican voters will think of Trump’s proposal — no pollster, as far as we can find, has directly asked about a “total and complete” ban on Muslims entering the U.S. Trump, however, evidently thinks his proposal is good politics: He retweeted a claim from Christian Broadcasting Network correspondent David Brody that the plan could “give [Trump] a boost with evangelicals,” a key group in the Iowa caucuses.

Cruz, Rubio and the other campaigns are arguably acting in their narrow best interest. Cruz’s campaign has been “drafting” off Trump’s for months, staying as close to it as possible without quite colliding with it. (It seems to be working: Cruz has been gaining in the polls, especially in Iowa.) Rubio has also been slowly but steadily improving in the polls and gradually adding endorsements to his tally. Kasich, Bush and Christie, who are struggling everywhere but New Hampshire, have much less to lose.

What’s more perplexing is the reluctance of Republican Party leaders to speak out against Trump. Republican Speaker of the House Paul Ryan declined to comment on Trump’s anti-Muslim proposal, for instance. Republican National Committee Chairman Reince Priebus hadn’t issued any statement as of late Monday night. And of the past three Republican nominees — George W. Bush, John McCain and Mitt Romney — only McCain had said anything.

Perhaps these Republicans are waiting to craft the right language — Romney, in particular, has had no trouble criticizing Trump before. Or perhaps they think any such statements wouldn’t be helpful — or could even backfire, given the distrust of the establishment that the GOP base has. It’s not clear that the GOP has anything in the way of a living elder statesman or stateswoman who has unimpeachable credentials to speak up about Trump. In a poll conducted by Gallup last year, the most admired male politician among Republican voters was … Barack Obama, who was chosen by 8 percent of Republicans. (George W. Bush was next, at 3 percent.) Condoleezza Rice (9 percent), Hillary Clinton (5 percent) and Sarah Palin (4 percent) were the most admired female politicians among Republicans.

But it’s also possible that the Republican reluctance to criticize Trump stems from a surfeit of short-term thinking — combined with a possible misreading of the polls. Several times so far in the campaign, we’ve witnessed the following cycle:

Trump says something offensive or ludicrous. Some pundits loudly proclaim that it could bring about the end of Trump’s campaign. Instead, Trump’s position remains steady or even improved in ballot-test polls. The same pundits therefore conclude that Trump is indestructible and impervious to criticism.

This is not a ridiculous interpretation. But there are some potential problems with it.

One is that most Republicans are still not paying all that much attention to the campaign. Some controversies that garner wall-to-wall coverage from the political press may only reach one-quarter to one-fifth of Americans at home. That mutes the impact of most things the candidates are doing. And any actual effects can easily be overwhelmed by noise in the polling, making it hard to make inferences about causality.

The second big problem is that in a field that still has 14 candidates, more media coverage — even negative media coverage — potentially helps a candidate to differentiate himself and thereby improve his position on the ballot test. In general, there has been a strong correlation between how well a candidate is performing on the ballot test and how much media coverage he’s receiving, although the causality is hard to determine. Trump seems to understand this; indeed, he seems to issue his most controversial remarks and proposals precisely at moments of perceived vulnerability.

Put another way, the media’s obsession over the daily fluctuations in the polls — even when the polls don’t predict very much about voter behavior and don’t necessarily reflect people who are actually likely to vote — may help enable Trump. Republicans are afraid to criticize Trump in part because it rarely produces instant gratification in a “win-the-morning” political culture that keeps score based on polls. Without seeing any repercussions, Trump goes farther out on a limb, shifting the window of acceptable discourse along with him and making it harder to rebuke him the next time around.

UPDATE (Dec. 8, 1:35 p.m.): Although a Trump spokeswoman initially said the ban would include American citizens traveling abroad, Trump said in an interview on Tuesday morning that citizens would be able to travel freely.