(CNN) Jay Sekulow is exactly who President Donald Trump has been looking for.

Most new legal advisers would be on thin ice after using a weekend media blitz to contradict their star client, a performance that earned poor reviews from traditional media outlets.

But Sekulow, who this weekend discounted Trump's tweeted claim that the President was under investigation over his firing of former FBI Director James Comey, has nothing to fear.

That's partly because he's vocally loyal to Trump, a quality the President has shown he prizes above most others. And from the evidence of his own radio show, Sekulow shares deep disdain for the political establishment that the President believes is bent on bringing him down.

"If the President of the United States asks you for legal advice, and if you are a lawyer and you are serving your country and the Constitution, you do it," Sekulow said June 9 on his radio show. "This is an attack on the presidency, that is what this is."

His flamboyant, fast-talking, performances on television show the kind of flair that Trump prizes in a surrogate. Other Republicans have not exactly been lining up to defend the President's wild tweets on television, and Trump's dissatisfaction with White House press secretary Sean Spicer emerged again Monday amid rumors he is about to be replaced.

More importantly, Sekulow, an agile lawyer who has argued before the Supreme Court, enjoys high credibility with conservative base voters.

He has been a frequent defender of the President on Fox News and other outlets, and was harshly critical of Comey's testimony before the Senate.

JUST WATCHED Trump lawyer: Comey firing doesn't violate law Replay More Videos ... MUST WATCH Trump lawyer: Comey firing doesn't violate law 02:37

As chief counsel of the American Center for Law and Justice, Sekulow -- a conservative response to the ACLU -- has successfully litigated culture war issues on behalf of pro-life and religious groups, earning a strong following among evangelicals.

So while it may appear to more general viewers and Washington insiders that Sekulow struggled to extricate Trump from the hole he dug with his tweet Friday, his energetic defense sent a message to voters the President can ill-afford to lose.

That's an important consideration in the months it will take for special counsel Robert Mueller to wrap up his investigation. The President's standing among GOP voters would be vital should his party ever face a question of whether to open House impeachment proceedings, should Mueller allege serious wrongdoing.

Still, among a less targeted audience, Sekulow's performance drew mockery.

"A lawyer creates a problem when he makes assertions of fact that run directly contrary to things his client has said in public that everybody heard him say," Democratic Sen. Sheldon Whitehouse told CNN's Wolf Blitzer Monday.

At one point, in an interview with Fox News Sunday , Sekulow stumbled, appearing first to argue that Trump was under investigation before he was pulled up short by host Chris Wallace.

"Sir, you just said two times that he's being investigated," Wallace said.

Sekulow replied: "I do not appreciate you putting words in my mouth when I've been crystal clear that the President is not and has not been under investigation. I don't think I can be any clearer than that."

JUST WATCHED Lawyer says Trump isn't under investigation Replay More Videos ... MUST WATCH Lawyer says Trump isn't under investigation 01:44

Lanny Davis, a former White House special counsel who played the Sekulow attack-dog role during the Bill Clinton impeachment saga, said that his friend had a tough hand because of Trump's tweet.

"He is a great lawyer who has to defend what is in effect a contradiction in the message of what he is truthfully saying," Davis told CNN's Brooke Baldwin.

Sekulow tried to get around Trump's claim that he was under investigation by dismissing it as a mere social media post, despite the White House's position that Trump's tweets are an authentic reflection of his views.

He said Trump was referring to a Washington Post story that he was under investigation, not a notification from Mueller, before attacking the story itself.

Sekulow also got in some political spadework that offers clues as to the White House's legal strategy ahead.

He tried to muddy the narrative about Comey's firing by reviving the original White House rationale that Trump acted on the recommendation of Deputy Attorney General Rod Rosenstein.

That argument is undercut by Trump, since the President told NBC News that the Russia probe was on his mind when he canned the FBI director. It's that claim that led critics to charge he was trying to obstruct justice.

Sekulow also advanced a White House effort to devalue Comey's testimony.

"I wouldn't exactly call James Comey a credible witness on this matter, period. I really don't," Sekulow told CNN's Chris Cuomo in a pugilistic encounter Monday.

JUST WATCHED Trump lawyer's full heated 'New Day' interview Replay More Videos ... MUST WATCH Trump lawyer's full heated 'New Day' interview 13:55

There's no doubt about Sekulow's loyalty to Trump.

But while his stock may be rising in Trump's eyes, some Republicans looked at his weekend antics with dismay.

"I don't think it is a winning strategy," former GOP Sen. Rick Santorum told CNN Monday. "Fighting this battle right now, trying to wage war with Bob Mueller right now, he needs to move on and focus on jobs and the economy and national security," said Santorum.

Sekulow is one of three recent high-profile hires by Trump as he faces the prospect that Mueller could decide to widen his probe. The President has also engaged veteran Washington lawyer John Dowd. He's also relying on his private lawyer Marc Kasowitz, who has represented him in legal actions for decades.

Mueller has been assembling his own high-powered team to handle the Russia investigation. He has brought in 13 lawyers and plans to hire more, his spokesman Peter Carr told CNN last week. They include James Quarles and Jeannie Rhee from his old firm WilmerHale, as well as Andrew Weissmann, who led the Enron investigation.