Sean Spicer finally put on his big-boy pants, manned up and apologized for the whopper of a doozy he served up this week when he compared Syrian President Bashir Assad’s atrocities to Hitler’s. Reporters say there were audible gasps in the press room when he said, “Someone who is as despicable as Hitler didn’t even sink to using chemical weapons.”

That was followed up by a couple of lame and blundering attempts by Spicer at cleaning up, while still trying to explain what he was trying to say. This only served to dig him a deeper hole.

Finally he realized he had no choice but to do the right thing and apologize. Good for him.

The problem is, in Sean Spicer’s position, in this particular situation, you cannot apologize your way back to credibility.

Sean has abused his position at the podium from the moment he first walked up to it and served up a hugely blatant lie, while scolding the press, about an issue as inconsequential as inaugural crowd size.

Sean Spicer defends inauguration claim: 'Sometimes we can disagree with facts' https://t.co/aVQBpXAqFV — The Guardian (@guardian) January 24, 2017

He seemed to think if he stated that Donald Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE’s inaugural crowd was bigger than Barack Obama Barack Hussein ObamaGOP senator blocks Schumer resolution aimed at Biden probe as tensions run high D-Day for Trump: September 29 Obama says making a voting plan is part of 'how to quarantine successfully' MORE’s, with enough intensity, repetition and persuasiveness, it would become true. But most of us know truth can be fact-checked, measured and, in this case, seen with our own eyes.

As bizarre as that debut episode was for Spicer, if that had been an anomaly, Spicer’s credibility could have been re-habilitated. But it wasn’t an anomaly.

In fact, it was only the beginning of a painful, almost daily ritual where Spicer would have to stand in front of the world’s media and either defend the indefensible lies that would spew out of Trump’s mouth that day — or roll off his twitter-happy fingers, more likely — or Spicer would invent untruths of his own in order to make his boss look good or to cover up for the myriad of inaccuracies in which the Donald Trump traffics on a daily basis.

Some say they feel bad for Sean Spicer. But Sean Spicer is there because he chooses to be there. No one is forcing him to be the mouthpiece of the lyingest presidential-candidate-turned-president we have had in the history of the Republic. That is of his own free will.

The bigger problem is that it would be virtually impossible for anyone to do that job well and with any degree of credibility while also answering to the audience of one — the president of the United States — that at the moment is the only one Sean Spicer cares about keeping happy. And the only way to do that is to unrelentingly defend the president’s lies and the ridiculous things he makes up at 5 in the morning on Saturdays and posts as his latest Twitter storm.

When Trump tweeted early one March Saturday morning about how Barack Obama had “wiretapped” Trump’s phones, and how Obama was a “bad” or “sick” guy for doing that, Sean Spicer tied himself up in knots coming up with new and interesting (and laughable) ways of trying to explain (defend) what Trump meant by that blatant lie.

How low has President Obama gone to tapp my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy! — Donald J. Trump (@realDonaldTrump) March 4, 2017

But if Spicer had gotten up there and plainly said what everyone knew to be true — expert after national security expert, including the FBI director himself, came out to say what Trump had tweeted had not a grain of truth to it — the press secretary would have been fired immediately. How do you tell the national media your boss is a habitual liar, so don’t pay attention to him? You can’t.

What is left is to either quit, because you realize that your obligation actually extends beyond the occupant of the White House and also includes an obligation to the truth, to the country and to the American people, or continue to trade on your credibility until it is so diminished that you are no good to your boss no matter what you say.

It seems we are at that point right now.

Sean Spicer should have quit early on.

As someone who has been in the communications business all her life, I know that, as a spokesperson in this town, all you have to trade on is the currency of credibility.

And Sean Spicer is currently in the red.

Maria T. Cardona is a principal at the Dewey Square Group, a Democratic strategist and a CNN/CNN Español political commentator. Follow her on Twitter @MariaTCardona

The views of Contributors are their own and not the views of The Hill.