President Trump and his team are deeply entangled in the controversy over the firing of FBI Director James Comey — and there are several potholes on the road ahead.

Top of the critical list is the extent to which Republican lawmakers distance themselves from Trump or stick by him.

On Friday, GOP dissent grew deeper when Sen. Dean Heller (R-Nev.) said the appointment of an independent prosecutor to look into alleged links between Trump campaign associates and Russia’s meddling in the presidential election “should be on the table” if congressional probes into the matter encounter obstacles. Heller is up for reelection next year, and his seat is widely seen as the top Democratic target.

The Nevadan is one of about a dozen GOP senators who have expressed concern or criticism about the president’s actions. 

Trump’s low approval ratings could also loosen the bond between him and his party colleagues on Capitol Hill. A Quinnipiac University poll released Wednesday — and conducted almost entirely before the Comey controversy erupted — gave him an approval rating of just 36 percent among registered voters, with 58 percent disapproving.

Republican nerves were further frayed Friday morning by a series of tweets from the president. Trump took aim at Comey, asserting that the fired FBI director “better hope that there are no ‘tapes’ of our conversations before he starts leaking to the press!”

Trump floated the idea of canceling the daily White House press briefing and wrote that “it is not possible for my surrogates to stand at [the] podium with perfect accuracy!” 

The tweet about Comey and “tapes” caused particular outrage, with critics of the president arguing that it was tantamount to a threat. Democratic Rep. Gerry Connolly (Va.) went so far as to accuse Trump of witness intimidation.

Later in the day, Speaker Paul Ryan (R-Wis.) parried reporters’ questions on Trump’s social media jabs, saying that he was “not going to comment on the tweets of the day or the hour.”

Ryan also sought to shift the focus onto likely replacements for Comey.

But the chances of the storyline moving onto more favorable territory for the president look slim.

Press secretary Sean Spicer declined to clarify during Friday’s media briefing whether conversations in the Oval Office or in the White House residence have been recorded. 

Chris Wallace of Fox News said on-air that one of those exchanges “took my breath away.” Wallace added that the administration was “playing a very dangerous game with the currency of the credibility of the president of the United States.”

Trump has other mounting worries. 

The way in which Comey’s firing was handled has caused consternation even among some of his staunchest allies. It has renewed speculation about the future of key members of his communications team, including Spicer. 

And it has led to yet another wave of leaks from within Team Trump after a period in which the White House appeared to have some success in putting a lid on its internal divisions.

Defenders of the president also noted ruefully on Friday that only eight days had elapsed since Republicans in the House had passed legislation aimed at dismantling and replacing the Affordable Care Act, also known as ObamaCare. 

The victory for Trump — which came after critics had pronounced his healthcare efforts dead and buried — feels like distant history now. The Comey controversy has become all-consuming.

Trump’s frontal assault on the former FBI director could also spur sources in or close to the bureau to leak damaging information on the president and his associates — a move that would entail potential legal peril for the leakers but which could embarrass Trump nonetheless.

The president could face some fraught moments on Capitol Hill next week. While Comey himself will not testify, despite being invited to do so, Deputy Attorney General Rod Rosenstein will brief the full Senate on the episode.

Considerable intrigue surrounds Rosenstein’s role. He wrote a now-famous memo to the president which was vigorously critical of Comey. But there were also some media reports — contested by the Department of Justice — that he had threatened to resign if he were cast as the driving force behind the director’s firing.

Trump’s political opponents are using his words to suggest he himself is skating close to legal difficulties. 

Sen. Dick Durbin (D-Ill.) on Friday said that Trump had come “dangerously close to obstruction of justice” when he had referenced the Russia controversy while discussing his reasons for removing Comey.

“When I decided to just do it, I said to myself — I said, you know, this Russia thing with Trump and Russia is a made-up story,” the president told NBC’s Lester Holt during an interview on Thursday.

Trump, as ever, remains defiant. 

In an interview with Fox News’s Jeanine Pirro broadcast Saturday, the president accused “the fake media” of “going crazy.”