A long-simmering fight is back on this week over the role of the infamous Donald Trump dossier after a new report that confirmed that the Democratic National Committee and Hillary Clinton's campaign helped fund it.

The battle over the unverified dossier is a crucial front in the broader political fight over the Trump White House, the public's perceptions of the president and his stunning election win.

The DNC and Clinton campaign's role in funding the dossier, which was reported by the Washington Post, doesn't add much to what was already public. It's been understood for months that the research that went into the document was initially underwritten by Trump's Republican opponents during the GOP primary season, and later taken over by Democrats during the general election campaign.

Still, the president and his supporters have seized on the new details about the DNC-Clinton role to push their view that the various Russia investigations — from Capitol Hill to Justice Department special counsel Robert Mueller — are based on a fraudulent, politically inspired hit job.

In short, they argue, if the dossier is the case that Trump's campaign colluded with Russia's attack on the election, that means there's no case.

Citing Fox News, Trump tweeted Wednesday morning, "Clinton campaign & DNC paid for research that led to the anti-Trump Fake News Dossier. The victim here is the President."

He later repeated to reporters on the South Lawn of the White House his sometime theory that the Russia collusion story is a Democratic hoax.

The president's allies have also taken up the message.

Erick Erickson, a conservative blogger and radio host, wrote that "both the DNC campaign apparatus and the Democratic leader, Barack Obama via his FBI, tried to dig up dirt on Trump."

"This should all be kept in mind as the Democrats continue to claim Russia stole the election and that Donald Trump has all sorts of nefarious ties to Russia," he added. "Many of those claims, now, appear to really have been generated in an incestuous relationship of sore losers."

For months, Republicans on the Hill have been trying to discover who specifically was behind the dossier. Its author is known, revealed as the former British intelligence officer Christopher Steele, who compiled the material for an American political investigation firm called Fusion GPS.

Political campaigns routinely pay outfits like Fusion GPS to generate "opposition research" on their adversaries. In this case, the desire to learn more about Trump's connections to Russia began with one of his primary opponents in 2016.

The identity of that campaign hasn't been confirmed, but Trump suggested on Wednesday he might know it.

Later — presumably after the initial Republican sponsor's campaign ended with Trump's victory in a primary — Democrats and Clinton's campaign began paying Fusion GPS to keep up its work, according to the Post. The FBI also is said to have paid Steele, although it cut off its relationship with him after his name became public.

The chairman of the Senate Judiciary Committee, Chuck Grassley, R-Iowa, has pushed the FBI for an explanation about how it used the dossier in its investigation of Russian interference in the 2016 election.

Republicans on the House Intelligence Committee, which is probing Russia's election role, have done so as well.

"It is relevant who paid for the dossier. It is much more relevant who relied upon it," Rep. Trey Gowdy, R-S.C., told Fox News on Wednesday. "So I want to know whether the nation's premier law enforcement agency relied on a document that looks like the National Enquirer prepared it."

House Intelligence Committee Chairman Devin Nunes, R-Calif., has gone over the heads of the panel's Democrats to subpoena Fusion GPS's bank records, which would likely show who paid for the research.

Fusion GPS has resisted, but a federal judge in Washington, D.C., is expected to rule on the matter soon.

For as much attention as the salacious dossier has gotten, there is wealth of public reporting that has confirmed certain elements in the document and a host of other things about ties between people in the Trump orbit and Russia.

The founding document of the FBI probe, now led by special counsel Mueller, is not the Steele dossier but the U.S. intelligence agencies' assessment from January 2016. That document lays out the intelligence community's view that Russia conducted a multifaceted influence operation to undermine American democracy, damage Clinton and help Trump win.

In May, Gowdy asked former CIA Director John Brennan whether his agency had relied on the unverified dossier in forming its conclusions about the Russian influence campaign. No, Brennan told him.

"It wasn't part of the corpus of intelligence information that we had," Brennan said. "It was not in any way used as a basis for the intelligence community assessment that was done."

The Kremlin campaign included hacking the DNC's computer systems, releasing pilfered communications to WikiLeaks to publish them, and a sophisticated overt propaganda and disinformation campaign.

The scale of the Russian efforts has come into focus in recent weeks as social media companies like Facebook and Twitter have revealed how Moscow's minions used their platforms to try to influence Americans and amplify divisions in U.S. society.

Public reporting has also nailed down multiple high-level contacts between people within the Trump orbit and Russians. And business contacts were not limited to those in Trump's immediate orbit. His own company, the Trump Organization, was in talks in January of 2016 about a proposed Trump Tower in Moscow.

Trump's longtime personal lawyer and a senior executive in the company, Michael Cohen, acknowledged emailing Russian President Vladimir Putin's spokesman to try to enlist his support with the stalled project.

Cohen said he ultimately abandoned the proposal for what he said were business reasons. He has denied any wrongdoing.

The fight over the dossier has helped contributed to the unraveling of the House Intelligence Committee's Russia probe as well as a similar investigation by the Senate Judiciary Committee.

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