In a court of law when it is discovered that evidence has been contaminated or a witness is lying, that evidence is thrown out and a jury is instructed to ignore the witness testimony.

As new bombshell revelations prove the infamous “Trump dossier” was bought-and-paid-for by Hillary Clinton’s presidential campaign and the Democratic National Committee, the document that launched the Russian collusion investigation against President Trump must accordingly be thrown out.

In light of the newest charge that the DNC and the Clinton campaign may have broken a dozen federal election laws with the document, special counsel Robert Mueller has no choice but to dismiss the Trump investigation.

To fully understand how the partisan hit piece fueled Mueller's Russian investigation, one must remember how it all began.

It was John Brennan, director of the Central Intelligence Agency under President Barack Obama, who accepted the now-debunked document and infused it into the bloodstream of the U.S. intelligence community. By acknowledging the document and logging it in his files, Brennan inadvertently gave the document a "Classified" rating, along with some hefty credence. The presumption among the intelligence community was that if the document was good enough for Brennan to believe, then it must have merit.

But Brennan has had a couple of missteps when it comes to intelligence in his career.

As CIA station chief in Riyadh, Saudi Arabia in 1996, Brennan’s CIA missed any signs of the bombing that was to come of the Khobar Towers which killed 19 servicemen.

In 2003, it was Brennan who advised President George W. Bush to establish an “Orange Terror Alert” during Christmas – only to have that intelligence later debunked.

As for the Trump dossier? Once it was injected into the bloodstream, the salacious document spread like wildfire throughout the intelligence community during a highly-charged election year.

That would be fine if the FBI were in the gossip business. But they’re not.

They’re in charge of pursuing actual threats to national security, not refereeing phony political hit jobs against Republicans.

Now, although no one in the Democratic Party will take responsibility for it and Fusion GPS’s co-founders refuse to testify for fear of incriminating themselves, some legitimate questions remain.

First, who gave Brennan the dossier?

Second, was he aware that the information was paid political fodder intended to damage the opposing party’s candidate? Or, as no fan of Trump himself, did he even care?

Lastly, it appears that Democrats were willing to use their contacts within the Deep State to accomplish their mission to smear Trump. It raises the question: Was Brennan aware that he might have been used as a tool of the DNC in infusing the document into the bloodstream of the intelligence community, where it would then take on a life of its own?

These questions remain, and Brennan should now be called to answer them.

As for the Russian collusion probe against Trump, it’s highly unlikely that Mueller will disband the probe on his own. After all, Mueller now presides over an office of 16 prosecutors and an unlimited budget in a town that values staff, unlimited budgets, and prestigious office space.

If the Russian collusion witch hunt against Trump is to end, it will have to be done by the president himself, Attorney General Jeff Sessions, or urged by Congress.

After more than a year of turning up no evidence that Trump colluded with Russia, and now equipped with new revelations that the Trump dossier was nothing more than a paid campaign piece, there is more than enough reason to justify disbanding the witch hunt once and for all.

Jennifer Kerns (@JenKernsUSA) is a contributor to the Washington Examiner's Beltway Confidential blog. A GOP communications strategist, she served as spokeswoman for the California Republican Party, recalls in Colorado, and California's Prop. 8. Previously, she served as a writer for the 2016 U.S. presidential debates for FOX News.

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