Democrats wrote to the Ukrainian government in May 2018 urging it to continue investigations into President Donald Trump’s alleged collusion with Russia in the 2016 presidential campaign — collusion later found not to exist.

The demand, which came from U.S. Senators Robert Menendez (D-NJ), Dick Durbin (D-IL), and Patrick Leahy (D-VT), resurfaced Wednesday in an opinion piece written by conservative Marc Thiessen in the Washington Post.

Ironically, Speaker of the House Nancy Pelosi (D-CA) declared Tuesday that the mere possibility that President Trump had asked Ukraine to continue an investigation of former Vice President Joe Biden — even without a quid pro quo — was enough to trigger an impeachment inquiry. (Biden boasted in 2018 that he had forced Ukraine to remove its prosecutor by threatening to withhold $1 billion in U.S. aid; he did not tell his audience at the Council on Foreign Relations that the prosecutor was looking into a firm on whose board his son, Hunter Biden, was serving.)

Thiessen observed (original links):

It got almost no attention, but in May [2018], CNN reported that Sens. Robert Menendez (D-N.J.), Richard J. Durbin (D-Ill.) and Patrick J. Leahy (D-Vt.) wrote a letter to Ukraine’s prosecutor general, Yuriy Lutsenko, expressing concern at the closing of four investigations they said were critical to the Mueller probe. In the letter, they implied that their support for U.S. assistance to Ukraine was at stake. Describing themselves as “strong advocates for a robust and close relationship with Ukraine,” the Democratic senators declared, “We have supported [the] capacity-building process and are disappointed that some in Kyiv appear to have cast aside these [democratic] principles to avoid the ire of President Trump,” before demanding Lutsenko “reverse course and halt any efforts to impede cooperation with this important investigation.”

The Democrats’ letter is available online here. In it, Menendez, Durbin, and Leahy demanded that the Ukrainian government answer their questions about the Mueller probe, and issued an implied threat: “This reported refusal to cooperate with the Mueller probe also sends a worrying signal — to the Ukrainian people as well as the international community — about your government’s commitment more broadly to support justice and the rule of law.”

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He earned an A.B. in Social Studies and Environmental Science and Public Policy from Harvard College, and a J.D. from Harvard Law School. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.