President Trump. Pool/Getty Images

After a week of tumult and negative news, the protective Republican wall around President Donald Trump is starting to crack.

Leading Republican politicians are becoming more vocal in their complaints, while networks are struggling to find Republicans willing to go on-air to defend the president.

The cracks come after a trio of bombshells. The first was Trump's controversial firing of FBI Director James Comey last week. He was let go while he was overseeing an investigation into potential collusion between the Trump campaign and Russian officials to swing the November presidential election in Trump's favor.

Next were reports on Monday that Trump had disclosed highly classified intelligence from an Islamic State-connected source — later revealed to be tied to Israel — with Russian diplomats during a recent Oval Office meeting.

The final eye-popper was a Tuesday report in The New York Times that said Comey kept memos of his meetings with Trump and documented one meeting in which the president reportedly said he hoped Comey would let go of the FBI's investigation into Michael Flynn, Trump's ousted national-security adviser. Legal experts outlined how that could lead to a "very strong case of obstruction of justice," the same charge that brought down former President Richard Nixon.

"We've seen this movie before," Sen. John McCain of Arizona said at a dinner for the International Republican Institute on Tuesday. "It's reaching Watergate size and scale. This is not good for the country."

Rep. Jason Chaffetz of Utah, the Republican chairman of the House Oversight Committee, tweeted Tuesday night following news of the Comey memo that he has his "subpoena pen ready" to obtain any memos that may exist of Comey's conversations with Trump. He said of the latest report: "On the surface that seems like an extraordinary use of influence to try to shut down an investigation being done by the FBI."

AshLee Strong, the spokeswoman for House Speaker Paul Ryan, said it was "appropriate for the House Oversight Committee to request this memo," citing a "need to have all the facts."

Jason Chaffetz. Chip Somodevilla/Getty Images

Chaffetz then sent a letter to acting FBI Director Andrew McCabe asking for all communications related to conversations between Comey and Trump.

Then, speaking at his weekly news conference on Wednesday, Ryan said the situation "requires close examination," doubling-down on a need for "the facts."

"We have an obligation to carry out our oversight no matter what party is in the White House," he said, adding that Chaffetz "appropriately requested the memo."

The Wisconsin Republican said there were "a lot of unanswered questions," and that it was "obvious" there were people who want to "hurt" Trump.

"Now is the time to gather all of the pertinent information," he said.

Asked about how he and his fellow House Republicans will be judged in the 2018 midterms, Ryan said he wanted people watching on TV to know that they're "busy fixing problems," and the Trump controversies are not all that is going on.

Sen. Lindsey Graham said in a statement Wednesday morning that, while he does "not believe in trial by newspaper article or investigations based on anonymous sources," Congress must call on Comey to testify before the Senate Judiciary Committee to "obtain a full understanding of what President Trump may or may not have done regarding the Russian investigation, including General Michael Flynn."

"The sooner Mr. Comey testifies publicly before the Judiciary Committee, the better for our nation," the South Carolina Republican said. "For all practical purposes the political process will be ground to a halt by these allegations."

"I will follow the facts — wherever they may lead," he added.

Lindsey Graham. REUTERS/Jim Bourg

Other Republicans, such as Reps. Mark Walker and Cathy McMorris Rodgers, expressed concerns at the Times report, with Walker telling CNN that "to act like it's not a concern would be remiss on my part," and McMorris Rodgers saying she thinks "the White House needs to be open and transparent about what's going on, too."

Meanwhile, after the news broke, networks were struggling to get any Republican lawmakers on air to discuss the president.

Charlie Rose said on CBS "This Morning" Wednesday that the network asked 20 Republican lawmakers and representatives at the White House to appear on air and all declined.

Fox News anchor Bret Baier of "Special Report" said Tuesday night that the network could not get a GOP member on air to defend Trump for his program.

"We've tried tonight to get Republicans to come out and talk to us, and there are not Republicans willing to go on camera tonight as of yet," Baier on his Tuesday program.

On the program that follows his — "The Story" with Martha MacCallum — Sen. Jim Risch of Idaho appeared on air to defend Trump, who won his state by more than 30 points.

Additionally, the White House's own statement defending Trump went unsigned, with no member of the administration tying their name to it.

But even before Wednesday, the tone of some statements began to sound more dire. Senate Intelligence Committee Chairman Richard Burr, a Trump backer who is leading the committee's Russia investigation, expressed frustration that the White House was not getting back to him as he was trying to figure out what Trump had said in his meeting with the Russians.

"There need to be serious changes at the White House, immediately," Sen. Pat Toomey of Pennsylvania told the Times.

While Republicans such as Toomey, McCain, Graham, Ryan, and Chaffetz were not exactly Trump's biggest backers during the election, it has become clear that the tenor is starting to change.

Sen. Bob Corker, chairman of the Senate Foreign Relations Committee and a onetime candidate to be Trump's running mate, told reporters Monday that the White House "has got to do something soon to bring itself under control and in order. It's got to happen."

"Obviously they're in a downward spiral right now and they've got to figure out a way to come to grips with all that's happening," he added.