On Saturday, Donald Trump ally and confidante Roger Stone declared that CNN “is not a news organization but an advocacy group” and that “when Donald Trump is president, he should turn off their FCC license.” (Full disclosure: I’m a CNN contributor.)

In any other election year, that would be news. But this cycle, Trump and his campaign have threatened the press in so many unprecedented ways that they’ve overloaded the system. The press itself can’t keep up. The day before Stone’s comments, Trump implied that he’d retaliate against The Washington Post’s critical coverage of him by going after its owner, Amazon CEO Jeff Bezos, who has been “getting away with murder, tax-wise” and has a “huge antitrust problem.” In March, Trump campaign manager Corey Lewandowski was arrested on misdemeanor battery charges for grabbing Breitbart reporter Michelle Fields at a campaign rally. (The charges were later dropped.) In February, Trump declared, “If I win … I’m going to open up our libel laws so when they [journalists] write purposely negative and horrible and false articles, we can sue them and win lots of money.” In January, the Trump campaign barred New York Times reporters from covering campaign events after the Times published an unflattering story about his ground operation. (At various times, Team Trump has also barred reporters from National Review, The Des Moines Register, Univision, BuzzFeed, The Daily Beast, Fusion, The Huffington Post, Mother Jones, and Politico, sometimes in explicit retaliation for negative coverage.)

There’s more. Trump has publicly called the journalists who cover him “scum” on at least two occasions. Last July, when The Daily Beast ran a piece about sexual-assault accusations by Trump’s ex-wife, Michael Cohen—executive vice-president at the Trump Organization—told the reporters who wrote it that “what I’m going to do to you is going to be fucking disgusting … I’m going to mess your life up.” As Vice’s Olivia Becker has noted, “Trump is the only presidential candidate whose rallies feature a specific area in the back where journalists are corralled and not permitted to leave. Other candidates have areas designated for the media, but reporters are free to mingle in the crowd to interview people. Leaving the press pen at a Trump rally [by contrast] comes with its own risk.” In February, when a Time magazine journalist tried to leave the pen to photograph protesters being ejected, a secret-service agent grabbed him by the neck and slammed him to the ground.

Most of what Trump is doing is not illegal. It just violates longstanding norms about how presidential candidates are supposed to behave. The danger is that, as America moves toward a general election in which commentators view Trump’s behavior through an increasingly partisan lens, Republicans will increasingly justify it. That will make it harder for the press itself to play watchdog because the media often defines objectivity as equidistance between the talking points of the two major parties. If Republicans rationalize Trump’s assault on press freedom as a necessary, hardball response to the media’s liberal, pro-Clinton bias, many journalists will treat that as a reasonable point of view. Thus, Trump’s behavior will be legitimized. And, of course, if Trump is elected president, his power to intimidate and restrict the press will expand exponentially.

Which is why I’m grateful to those conservatives who remain #NeverTrump. It’s easy for liberals to mock conservatives who, after turning a blind eye when more mainstream GOP candidates flirted with bigotry, express outrage at The Donald. (Where was the conservative indignation when Scott Walker said he didn’t know if President Obama was a Christian, when Jeb Bush said America should accept only Christian refugees from Syria, or when Marco Rubio called Obama divisive for visiting a mosque?)

Still, the Never Trumpers deserve credit. In America today, party is tribe. For many in Washington, it’s also a feeding trough. So by loudly denouncing the man who has, for the time being, taken over the GOP, the Never Trumpers are doing something brave. They’re also an essential bulwark against the legitimization of Trump’s thuggery. If high-profile conservatives denounce Trump’s intimidation of journalists, his proposed Muslim ban, and his endorsement of torture, then it’s less likely that “objective” reporters and TV anchors will treat Trump’s actions as merely one side of a partisan, he-said/she-said. As the electorate moves toward the official general election, anti-Trump conservatives, because they can’t be accused of pro-Clinton bias, will become crucial gatekeepers of longstanding norms of political decency. In the unlikely event that Trump wins this November, they’ll be essential to protecting the republic.

In 2016, conservatives are being tested in a way not seen in most Americans’ lifetimes. David Brooks has called it a “McCarthy moment.” But it’s bigger than that; Joseph McCarthy never had a shot at the presidency. Some conservatives are failing. Others are rising to the occasion in honorable and impressive ways.

The next time you read about Trump threatening journalists, or demonizing vulnerable minorities, or proposing war crimes, pause and be grateful for those conservatives willing to oppose him. America will need them dearly in the months to come.