There have been reports recently that the Senate Intelligence Committee, the panel conducting the bipartisan flagship congressional investigation of the Trump-Russia affair, has not found evidence to conclude that the Trump campaign colluded with Russia to fix the 2016 election.

"If we write a report based upon the facts that we have, then we don't have anything that would suggest there was collusion by the Trump campaign and Russia," the committee's chairman, Republican Sen. Richard Burr, told CBS last week.

Pressed on his statement a few days later, Burr said, "The only thing I've addressed is whether we had facts that suggest there was [collusion]. We don't have any." Burr added one caveat: "Just saying what factually we've found to date. We haven't finished our investigation."

At about the same time, NBC News reported that committee Democrats did not fundamentally dispute Burr's statement, although they emphasized they had uncovered no "direct" evidence of collusion. "Both Republicans and Democrats are telling us that they found no direct evidence of a conspiracy between the Trump campaign and Russia, which after all was the big question that everyone was asking," said NBC's Ken Dilanian Tuesday.

The talk prompted pushback from the top Democrat on the Intelligence Committee, Sen. Mark Warner, who told CNN that he is not on board with Burr. "Respectfully, I disagree," Warner said. "I'm not going to get into any conclusions I've reached, because my basis of this has been that I'm not going to reach any conclusion until we finish the investigation. And we still have a number of the key witnesses to come back."

The "no collusion" talk set off alarm bells among those who have devoted the last two years to promoting the notion that Trump and Russia conspired in 2016. The Committee to Investigate Russia, established by actor Rob Reiner and including former intelligence chiefs James Clapper and Michael Hayden, sent out an email headlined, "No Direct Link So Far ... But So What?"

Likewise, Harvard law professor Laurence Tribe was in no mood to entertain a "no collusion" argument. "Burr is out on a limb that his non-GOP colleagues are sawing off," Tribe tweeted Tuesday. "He's being a partisan. Plus his definition of 'evidence' is wildly unrealistic. Nobody ever imagined Trump saying to Putin, 'Hey, I'll lift the sanctions if you make me president.' That's not how it works."

For her part, MSNBC's Rachel Maddow seemed to take issue with her own network's reporting by tweeting out a Mother Jones story headlined, "Senate Intelligence Committee Democrats Dispute Claims That Russia Probe Found No Collusion." The story featured a quote from Warner saying, "The president is terrified about where our investigation ... may lead."

Some might be particularly distressed by the prospect that the Senate could reach the same verdict on collusion as House Intelligence Committee Republicans did in a report that was widely derided in some media circles last year.

The committee's Republicans, led by then-chairman Rep. Devin Nunes, "found no evidence that the Trump campaign colluded, coordinated, or conspired with the Russian government," the report said. Nevertheless, GOP lawmakers added, "the investigation did find poor judgment and ill-considered actions by the Trump and Clinton campaigns."

Democrats mocked the report and its no-collusion conclusion. The document was "rife with significant inaccuracies, mischaracterizations, vital omissions of fact and context, and often risible attempts to explain away inconvenient truths," committee Democrats said in a minority report.

"This was basically a kindergarten exercise where they brought in witnesses, let them say what they were going to say, took them at their word, and said, OK guys, we're all done here, no collusion," said Democratic Rep. Joaquin Castro, an Intelligence Committee member.

"Let me just say that this Republican report from the House Intel Committee really is a fake report," Democratic Rep. Ted Lieu said. "They had the view that there was no collusion. Of course, they're going to do a report that shows there's no collusion because they weren't looking for it, and they were actually trying to ignore evidence of collusion."

Senate Intelligence Committee investigators were not trying to ignore evidence of collusion. But now, it appears they, too, are headed for essentially the same conclusion as House Republicans.

Even more concerning to some Democrats is that the news from Burr came on the heels of stories to the effect that Trump-Russia special counsel Robert Mueller might not charge Trump associates with conspiracy and might not even allege that the much-discussed Trump-Russia conspiracy even occurred. Many House Democrats have been relying on Mueller to give them a roadmap and cover to initiate impeachment proceedings against the president. Now, they face the question of what to do if Mueller does not give them what they want.

The answer could be that House Democrats will have to do the job by themselves. Frustrated by Republican control the last two years, followed, potentially, by the failure of both the Senate Intelligence Committee and the Mueller investigation to provide proof of collusion, bound-and-determined House Democrats will have to rely on themselves to come up with grounds to impeach Trump. That is one reason why the talk in the House today is of new investigations that will go where Mueller could not, and finally uncover evidence of impeachable offenses. If the Senate and Mueller investigations reach a disappointing end, Democrats might have to go it alone.