U.S. House Speaker Nancy Pelosi has characterized her decision to delay sending the Senate two articles of impeachment the House approved last month as an attempt to pressure Senate Majority Leader Mitch McConnell.

Like many, she'd prefer a serious trial on the allegations that President Donald Trump conditioned the release of $391 million in congressionally approved military aid to Ukraine announcing investigations into Democratic presidential candidate Joe Biden and his son Hunter. Given that last month, McConnell told Fox News host Sean Hannity that he would handle the trial "in total coordination with the White House Counsel's Office and the people who are representing the president," Pelosi's concerns are understandable.

But McConnell has demonstrated he has 51 votes to run the Senate trial without accepting preconditions sought by Pelosi and Senate Minority Leader Chuck Schumer. Recognizing this, at least seven Senate Democrats — Dianne Feinstein of California, Joe Manchin of West Virginia, Jon Tester of Montana, Chris Coons of Delaware, Doug Jones of Alabama, and Richard Blumenthal and Chris Murphy of Connecticut — told Politico, CNN and the Washington Post that it was time for Pelosi to send the articles of impeachment to the Senate.

"The longer [the impeachment process] goes on, the less urgent it becomes," Feinstein said. "So if it's serious and urgent, send them over. If it isn't, don't send it over."

Meanwhile, Senate Republicans who may actually want to have a trial with integrity — such as Mitt Romney and Mike Lee of Utah, Susan Collins of Maine and Lisa Murkowski of Alaska — will have the chance to make this clear. Former Trump national security adviser John Bolton's surprise offer to testify if subpoenaed by the Senate has already been rejected by McConnell.

But if four Republicans agree with the Senate's Democratic caucus on subpoenaing Bolton, that would result in a trial of much more substance — at least if Bolton chose to be forthright about his reported view that Trump's pressure on Ukraine was akin to a "drug deal."

None of the officials who have testified that Trump explicitly linked Ukraine's receipt of the military aid to Ukraine's help smearing a political rival are or were nearly as high-ranking. And none have Bolton's stature among Republicans after decades as a central figure in GOP foreign policy circles. Damning testimony from him would make it more difficult for Trump to dismiss the Ukrainian scandal as a "deep state" plot. Bolton has already said his testimony would follow "careful consideration and study." One can expect him to be honest.

Since Trump is more popular than any other Republican, it's nearly impossible to imagine that there are 67 votes in the Senate to remove him from office. Yet it's fair to hope that 51 U.S. senators will take seriously allegations of misconduct by the president — and want to hear from a credible witness with firsthand knowledge of Trump's actions.

FROM AN EDITORIAL IN THE SAN DIEGO UNION-TRIBUNE