There’s a reason that Chris Christie won’t win the Republican nomination for President and Bill Cosby may never perform stand up again.

They’re both perceived to be hiding the truth; or, stated a tad less politically correct, lying.

The citizens of New Jersey have, according to the polls, largely given up on their portly governor, and he – judging by his love affair with the loathsome Jerry Jones in Dallas and his growing absences from the state – on them.

Christie’s steep decline, of course, stems from the infamous Bridgegate scandal of a year ago, and the governor’s initial reluctance and later sparse commentary about any role in he may have played in purposely causing traffic jams on the George Washington Bridge.

Basically, Christie feigned ignorance of the whole mess, blaming the tie-ups on the rogue actions of a long-term subordinate, who owed her career to him and rarely acted without his approval.

In other words, Christie’s convenient passing the blame onto a hapless subordinate simply didn’t wash; especially for one who has presented himself as a tough, hands-on manager. Christie was perceived as a liar, and his political upward mobility is over.

The same can be said for Cosby, the erstwhile role model, now dogged by endlessly-escalating charges of sexual abuse. Cosby’s lawyer – but not Cosby, himself – has denied the charges. Having a lawyer profess your innocence is, of course, the least-convincing proof an accused individual can serve up.

As Cosby continues to dig a deeper hole by lamely joking about the mounting accusations against him, he has become a pitiable character. The comedian can’t be saved. His failure to tell the truth has rendered a death knell on his career.

Now contrast the fate of these truth deniers with that of two others, one who admits his guilt, the other who professes his innocence, lawyer Alan Dershowitz and newsman Steve Kroft.

The combative Dershowitz was accused recently of having sex with an underage girl, hired by his former client, sleaze ball investor Jeffrey Epstein. The girl’s lawyers singled out Dershowitz and England’s Prince Andrew as recipients of convicted sex offender Epstein’s largesse.

While Prince Andrew was mum in the face of the allegations, Dershowitz came storming out with both barrels blazing, insisting he had never even met his accuser. Dershowitz took his case to CNN, "Today" Show, the Hollywood Reporter and anybody else who cared to listen.

Said the embattled counselor, “I’m going to demolish this woman’s credibility and prove she’s a serial liar. I won’t rest until the lawyers admit they made it up.” He also promised to have the woman’s lawyers disbarred as a result.

So rather than hiding or ignoring the damning allegations, Dershowitz did just the opposite. He sought out public attention, because, presumably, the truth was on his side.

And finally, there was poor, cornered Steve Kroft, the CBS “60 Minutes” newsman, outed by the National Enquirer for an adulterous affair with a mistress.

While others might have let the whole, sordid tale play itself out without comment, to the glee of the New York Post, Daily Mail and like-minded purveyors of scandal – Kroft took the high road in his low-life tale.

The chastened newsman acknowledged his dalliance, “I had an extramarital affair that was a serious lapse of personal judgment and extremely hurtful to my wife and family, and for that I have nothing but regret.”

Gravely embarrassed? Of course. Damaged credibility? Without question. But the difference between Kroft, who admitted the truth, and Christie and Cosby, who didn’t, is that the former’s career will continue, relatively unimpeded, while the best days of the latter two are clearly behind them.