With the first indictments, and more significantly the first guilty plea, the investigation led by Special Counsel Robert S. Mueller III is moving toward confirmation of the worst fears the American public had when Mueller began the inquiry in May: Not only did Russian agents interfere in the 2016 U.S. presidential election to tilt the outcome in favor of one of the candidates, but did so in collusion with the campaign that benefitted from that skullduggery.

While collusion of top Trump officials has yet to be demonstrated, the signals point in that direction.

The biggest surprise Monday was the revelation that the FBI had arrested George Papadopoulos, a foreign policy advisor to the Trump campaign, back in July. He recently pleaded guilty to lying to the FBI and has been cooperating with investigators.

According to the plea agreement, Papadopoulos lied about the timing and circumstances of his meeting with a Russian agent to learn “about the Russians possessing ‘dirt’ on then-candidate Clinton in late April 2016, more than a month after defendant Papadopoulos had joined the (Trump) Campaign."

The documents also references Papadopoulos as consulting with campaign advisers about the dirt the Russian operative possessed, including “thousands of emails,” which the public now knows were stolen from private Democratic communications by Russian hackers.

In simplest terms, Papadopoulos connects the Russian government to the Trump campaign, and he’s talking about it and potentially about efforts to cover up that connection.

President Trump and his surrogates are seeking to dismiss Papadopoulos as a low-level and insignificant volunteer in the campaign. But belying that depiction is Trump’s statements to The Washington Post Editorial Board in March 2016 that he was among his top foreign policy advisors and an “excellent guy.”

The president sought to make much of the fact that the two indictments announced Monday — filed against former Trump campaign manager Paul Manafort and his associate, Rick Gates, who also worked on the campaign — had no link to Russian meddling in the election.

That Trump is left spinning as good news the indictment of his former campaign manager and Gates — both accused of laundering millions of dollars in payments for helping to politically prop up a Russian puppet government in Ukraine — shows how desperate is the president’s situation.

The obvious conclusion is that Mueller, in pursuing serious charges that could land Manafort in prison for a long time, is putting the screws to the defendant to entice his cooperation in what is certainly an expanding Russian investigation.

Trump brought Manafort into his campaign with eyes wide open. The list of corrupt strongmen to which Manafort had provided consulting included Jonas Savimbi in Angola, Mobutu Sese Seko of the Democratic Republican of Congo, Ferdinand Marcos of the Philippines and, yes, the Kremlin darling, Ukrainian President Viktor Yanukovych, driven from office by a popular uprising in 2014. Despite this ugly record of enriching himself, Manafort apparently brought something to the table that Trump wanted.

In response to the breaking news the White House resorted to its usual tactics, trying to gin up interest in unrelated and dubious scandals, Trump tweeting “NO COLLUSION,” and his press secretary telling reporters the events had nothing to do with the president.

Mueller will not be distracted, and neither should the public.

Then there is this. If the president has nothing to hide and nothing to fear, why is he not welcoming the investigation? And why does he not condemn the efforts of a foreign enemy to meddle in our elections, rather than trying to discredit the probe?

Congress must play an important role in this process. So far the House and Senate investigations into Russian interference in the 2016 election have been slow to roll out and lacking in transparency.

With the likely potential for more indictments to come, today’s Congress should look to the Select Committee on Presidential Campaign Activities, better known as the Watergate Committee, which acted in bipartisan fashion to get at the central evidence of the scandal that drove President Nixon from office, and did so with a process in full view of the public.

On this matter — what was the nature of the Russian election interference and was there collusion — both Democrats and Republicans must set partisan politics aside. Congress needs to follow the facts where they lead, without thought of political gain or to manage political damage.

Past elected leaders stepped up in a time of constitutional crisis and today’s leaders must prepare to do the same.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.