When then-FBI Director James B. Comey explained to Congress last March the scope of his investigation into President Trump’s aides and Russia his words would also fit the Hillary Clinton campaign today.

Mr. Comey told the House Intelligence Committee that his agents were investigating “whether there was any coordination between the campaign and Russia’s efforts.”

That definition — “coordination” — would seem to make the Democrats ripe for Special Counsel Robert Mueller to investigate, Trump ex-aides say.

What is known now that was not known in March: the Clinton campaign and the Democratic National Committee paid for an opposition research operation against Mr. Trump during the 2016 election that relied almost exclusively on paid Kremlin sources and Russian spies.

The Russians plied British ex-spy Christopher Steele with what Trump people term lies and fiction that became part of a dossier. The dossier or its contents were spread around Washington by Mr. Steele and his employer, Fusion GPS, which got the money from the Clinton campaign and the DNC.

“If there was enough Russia collusion evidence to warrant a special counsel for the president, there’s far more now on the Clinton campaign’s connection to a foreign spy ring that included Russians,” said Michael Caputo, a former Trump campaign communications adviser. “That, coupled with the stymied investigation into the Russian bribery plot and donations directed to the Clinton Foundation, are grounds for a special counsel.”

Hired in June 2016, Mr. Steele used the flow of cash from Democrats and Fusion to pay Russians to dish dirt on Mr. Trump and his aides.

According to court filings in a libel suit against Mr. Steele, the ex-spy said he got specific instructions from Fusion GPS to dig up coordination between Trump people and Russia. Starting in mid-June, he filed 18 memos, some of which became fodder for anti-Trump news stories and for Hillary Clinton press releases and TV surrogates to link the Republican to Russia.

The public knows today who funded the dossier because House Intelligence Committee Chairman Rep. Devin Nunes, California Republican, issued a subpoena to Fusion’s bank demanding financial records. That prompted the Clinton’s campaign law firm, Perkins Coie, to admit last Tuesday that it funneled money from the campaign to Fusion.

Here is how Mr. Comey, whom President Trump fired as FBI director, defined his investigation to the committee last March.

“I have been authorized by the Department of Justice to confirm that the FBI, as part of our counterintelligence mission, is investigating the Russian government’s efforts to interfere in the 2016 presidential election and that includes investigating the nature of any links between individuals associated with the Trump campaign and the Russian government and whether there was any coordination between the campaign and Russia’s efforts. As with any counterintelligence investigation, this will also include an assessment of whether any crimes were committed.”

Said J.D. Gordon, a former Pentagon spokesman and a Trump campaign national security adviser, “Considering what we’ve learned in recent days about the sources of Fusion GPS funding, I imagine that Hillary’s campaign and the DNC will be investigated by the Special Counsel.”

“Those who committed crimes against Trump associates to include members of Congress, such as cyberstalking, libel and slander, should also be included in these far reaching probes,” he said. “We must put an end to this neo-McCarthyism that’s swept over Washington.”