Josh Campbell is a CNN analyst covering national security issues. He previously served as a supervisory special agent with the FBI, special assistant to the bureau's director, and is writing a book on recent attempts by elected officials to undermine the rule of law. Follow him on Twitter at @joshscampbell . The views expressed in this commentary are his own. View more opinion on CNN.

(CNN) "When you're attacking FBI agents because you're under criminal investigation, you're losing," Sarah Sanders, then a Donald Trump campaign aide, famously said of Hillary Clinton supporters before the 2016 presidential election. Although she has repeatedly struggled with the facts -- and now serves as White House press secretary -- Sanders' apt tweet remains wisdom for the ages.

Both President Donald Trump and Sanders have led the charge against special counsel Robert Mueller and his team of prosecutors investigating the Trump campaign's possible ties to Russia and other crimes unearthed in that endeavor. Trump has repeatedly called the investigation a "witch hunt" in an attempt to paint Mueller and his team as a band of corrupt authorities trying to bring down an innocent President. The closer Mueller gets, the more caustic Trump becomes.

On Thursday, we saw yet another round of efforts to attack investigators after Michael Cohen, the President's former lawyer and fixer, pleaded guilty to lying to Congress about Trump's business dealings with Russia. While the President has maintained he had "nothing to do with Russia," Cohen told a federal court on Thursday that, acting as Trump's representative, he had been in communication with the Russian government about a proposed Trump Tower in Moscow during the presidential campaign. Cohen previously told Congress that talks surrounding the project ended before the Iowa caucuses, but they continued for at least six months longer.

Faced with the new revelations made public by his lawyer-turned-nemesis, Trump returned to familiar territory and lashed out against his accuser, along with Mueller and the investigation as a whole. He called Cohen a weak liar, while branding Mueller and his team of independent public servants "a total disgrace."

To bolster his case, Trump went on to amplify the words of various fire-breathing commentators on Fox News, which has often served as a mouthpiece for the President during his ongoing attempt to discredit Mueller. Remarkably, Sanders issued a statement on Friday suggesting Mueller's investigation "probably does undermine our relationship with Russia," while saying nothing about the Kremlin's documented efforts to interfere with America's sacred electoral process.

Time is running out for Trump, because the patience of the American people is not without limit. The public understands that elected leaders are not perfect, but they will not accept a continued pattern of demonstrated deception. With Trump, we have seen countless instances of his categorical denials completely subsumed by the facts.

While Sanders denied in 2017 that Trump dictated a misleading statement to The New York Times regarding his son Donald Trump Jr.'s 2016 Trump Tower meeting with Russians, we now know Sanders' statement was false . We also know the President personally directed a $130,000 payment to Stormy Daniels just days before the 2016 election, despite his complete denial of any knowledge of the matter.

We have further learned that the President's full-throated claim that he had had no business ties with Russia was false (in an effort to rationalize his behavior, the President himself tweeted on Friday that he "lightly" looked at a building project in Russia).

As Trump's statements are continually found to be false and Mueller's progress is revealed in court documents, many are beginning to see the light. The tired yarn that Trump sits at the center of an out of control "deep state" hellbent on bringing him down has now become quaint, eliciting yawns and eye-rolls from the national security professionals I am frequently in contact with. The unyielding scrutiny on Trump's potential ties to Russia may feel like the work of circling sharks for those in the crosshairs of the Mueller investigation, but many of us see a system working as it should to hold the powerful to account.

In February, I wrote that many people inside the FBI believe Trump was trying to undermine the institution for the sole purpose of discrediting Mueller's findings. It was true then and it remains true now. However, what none of us could have predicted at the time is that Trump's repeated denials would be met with such a cascade of overwhelming evidence suggesting he has not been truthful with the American people.

For more opinion... Sign up for our new newsletter. Join us on Twitter and Facebook

Fortunately for our institutions of justice, each new exposed lie is further evidence that those in the Justice Department are not corrupt; they are simply doing their jobs and following the facts wherever they lead. If the Trump associates that Mueller has continued to knock down were indeed innocent, the President might be spending his time presenting facts to prove the case rather than attacking Mueller and the investigation. And we all know that when you're attacking investigators, you're losing.