As the investigation of the Trump campaign's collusion with Russia creeps toward the presidency, Fox News, the GOP, and Trump himself are attacking the key to implicating Trump's obstruction of justice.

Republicans have launched what certainly appears to be a coordinated attack against former FBI Director James Comey to undermine testimony that Donald Trump tried to obstruct justice.

A mere 24 hours after Sen. Chuck Grassley (R-IA) spoke to Trump over the phone, Grassley released a letter, along with his Republican colleague Sen. Lindsey Graham, making a bold accusation against Comey.

The letter alleges that Comey, while investigating Hillary Clinton’s emails, had drafted a statement exonerating Clinton before the formal conclusion of the investigation. Grassley and Graham use the claim to make the allegation that Comey operated under the principle of “Conclusion first, fact-gathering second.”

In her press briefing Thursday, White House press secretary Sarah Huckabee Sanders said if the allegations in the letter are true, they would justify Trump firing Comey. But Trump has already gone on record and admitted that he was thinking about the intensifying Russia investigations when he fired Comey, and reporting has shown that he was pressuring officials to drop the case — including Sen. Mitch McConnell.

On Friday, Trump amplified Grassley’s letter, tweeting, “Wow, looks like James Comey exonerated Hillary Clinton long before the investigation was over…and so much more. A rigged system!”

Once again filling the role of Trump’s quasi-official propaganda network, Fox News amplified the allegation in Grassley’s letter in a segment on “Fox & Friends” — Trump’s favorite show. Disgraced former congressman Jason Chaffetz even floated the idea that Comey had committed perjury and has a lot of “explaining to do.”

But the Trump-Grassley-Fox story is already crumbling. A source familiar with the inner workings of the investigation told CNN the allegation doesn’t have much ground to stand on. The news outlet reported that a second source backed up that information, writing, “A second person familiar with the matter told CNN that Comey had not already made up his mind, and that it did not influence the investigation. ”

The right’s pro-Trump propaganda campaign has kicked into gear in the same week that Trump’s lawyers quietly sent memos to special counsel Robert Mueller’s office arguing that Trump didn’t obstruct justice, showing that the serious allegation is at the top of their minds.

Mueller met with New York’s attorney general, Eric Schneiderman, and discussed possible money laundering by former Trump campaign chairman Paul Manafort. If Manafort were prosecuted for breaking state law, it would prevent Trump from pardoning him.

It was also revealed this week that Trump’s inner circle was speaking to Russians about opening a new Trump property in Moscow, just as Trump started using his presidential campaign to praise Vladimir Putin.

That is the series of incriminating developments under which Senate Republicans, Trump, his press flack, and Fox News all began pushing a smear against former FBI director James Comey, who was subjected to pressure from Trump over the Russia investigation and figures to be a key element of any future action against Trump.

Trump and his Republican allies in Congress and on Fox News are trying to muddy the waters because the country does not want him to continue to meddle in the investigation as he repeatedly has. Americans want to know just how tainted by foreign influence and interference Trump’s presidency truly is.

His disinformation campaign wants to avoid the truth and to attack those who have exposed him and the inner workings of his unpopular presidency.

What Trump and his team have done went so far beyond the norms of behavior for a presidential candidate that it is unlikely any sort of propaganda campaign could work to truly cover it up. But Trump is going to try.