Donald Trump's war on the media is exposing a deep rift in the Republican Party.

The president's loyalists are eagerly joining his crusade against so-called "fake news", but others on the conservative side of American politics have recoiled at what they see as authoritarian-style rhetoric from the White House.

Senator John Mccain, who was the Republican presidential nominee in 2008, is one of those worried Republicans. He issued a stark warning during an interview with NBC's Chuck Todd overnight.

"I hate the Press. I hate you especially," Mr McCain joked. "But the fact is we need you. We need a free press. We must have it. It's vital.

"That's how dictators get started. They get started by suppressing the free press. In other words, a consolidation of power. When you look at history, the first thing that dictators do is shut down the press. And I'm not saying that President Trump is trying to be a dictator. I'm just saying we need to learn the lessons of history.""If you want to preserve - I'm very serious now - if you want to preserve democracy as we know it, you have to have a free and many times adversarial press. And without it, I am afraid that we would lose so much of our individual liberties over time.

Mr McCain is no friend of the president. They have been exchanging potshots since the early weeks of Mr Trump's presidential campaign, when he impugned Mr McCain's reputation as a hero of the Vietnam War.

"He's not a war hero. He was a war hero because he was captured. I like people who weren't captured," Mr Trump said.

Mr McCain, who served as a Navy pilot in Vietnam, spent five years in a prison camp after being shot down. He was repeatedly tortured, but refused to accept a deal that would have seen him released before his fellow prisoners.

When Mr Trump was called out for his comments he doubled down, calling Mr McCain "yet another all talk, no action politician who spends too much time on television and not enough time doing his job".

It isn't a one-way street though. Mr McCain has emerged as one of Mr Trump's chief critics, slapping him down on issues such as torture, foreign policy and the bungled military raid that led to the death of a Navy SEAL.

The continuing feud between the pair is symptomatic of how uncomfortable many Republicans still are with Mr Trump. Other politicians, such as senators Lindsay Graham and Marco Rubio, have openly criticised the president, and called for an investigation into Russia's interference in last year's election.

Conservative political commentators are also worried. For example, David Frum's cover story for March's issue of The Atlantic is one long warning about the dangers of Mr Trump's presidency.

"More than any other president in US history since at least the time of Andrew Jackson, Donald Trump seeks to subvert" the institutions that protect democracy, Mr Frum writes.

"By all early indications, the Trump presidency will corrode public integrity and the rule of law, and also do untold damage to American global leadership, the Western alliance and democratic norms around the world. The damage has already begun."

Mr Trump's supporters, however, aren't buying it. They believe the media - and politicians like Mr McCain - are the problem.

"It was McCain up to his old tricks. Ingratiating himself to the anti-Trump press by playing its champion, in a bid to be the media's darling," said American Thinker writer Monica Showalter.

"What stands out here is the hypocrisy of his claims. He's suddenly concerned about press freedoms and dictators? Where was McCain when President Obama was systematically violating press freedoms every which way to Tuesday?"

Senator Rand Paul, another of Mr McCain's Republican colleagues in Congress, said America is "very lucky John McCain is not in charge".

"John McCain has been wrong on just about everything over the last four decades," Mr Paul told ABC News. "I don't agree with his analysis and applying that to the president. I haven't seen any legislation coming forward that wants to limit the press. I see President Trump expressing his opinion, rather forceful in his own - you know, his own distinct way."

Drudge Report, a pro-Trump site, called Mr McCain a "bitter man who lost his White House chance". Breitbart News, whose former chairman Steve Bannon is now Mr Trump's top adviser, gloated that the media had taken the president's bait by "sputtering" about his "fake news" claims.

There has been extensive coverage of Mr Trump's comments, particularly in the aftermath of his press conference last week, which left several prominent journalists openly frustrated.

"It was a wild press conference," CNN anchor Jake Tapper said. "It was an airing of grievances. It was Festivus. It was complaints about the media. And one point he said the leaks are real but the news is fake, which doesn't make any sense whatsoever. He said things that were not true.

"It was unhinged, it was wild, and I can't believe that there are Republicans who don't understand that that might play well with the 44 per cent of the population who voted for the president, but a lot of Americans are going to watch that press conference and think, 'that guy is not focused on me, I don't even know what he's focused on'.

Over at Fox News, anchor Shepard Smith joined the rant-fest.

"It's crazy what we're watching every day. It's absolutely crazy. He keeps repeating ridiculous throwaway lines that are not true at all, and sort of avoiding the issue of Russia as if we're fools for asking the question. Really? Your opposition was hacked, and the Russians were responsible for it, and your people were on the phone with Russia on the same day it was happening, and we're fools for asking the questions? No sir," Mr Smith said.

"We demand to know the answer to this question. You owe this to the American people. Your supporters will support you either way. If your people were on the phone, what were they saying? We have a right to know, we absolutely do. That you call us fake news and put us down like children for asking these questions on behalf of the American people is inconsequential. The people deserve that answer."

"President Trump, if you're watching, you legitimately won the presidency. Now get to work, and stop whining about it."

Over at Fox News, anchor Shepard Smith joined the rant-fest.

"It's crazy what we're watching every day. It's absolutely crazy. He keeps repeating ridiculous throwaway lines that are not true at all, and sort of avoiding the issue of Russia as if we're fools for asking the question. Really? Your opposition was hacked, and the Russians were responsible for it, and your people were on the phone with Russia on the same day it was happening, and we're fools for asking the questions? No sir," Mr Smith said.

"We demand to know the answer to this question. You owe this to the American people. Your supporters will support you either way. If your people were on the phone, what were they saying? We have a right to know, we absolutely do. That you call us fake news and put us down like children for asking these questions on behalf of the American people is inconsequential. The people deserve that answer."

Were those reactions overblown? Was John McCain exaggerating when he claimed this is "how dictators start"? Or is Donald Trump truly going too far?

Whatever the answers, the schism in American politics, which extends to Mr Trump's own party, is not healing - it's growing wider. And that seems to suit the president just fine.