Jonathan Bernstein: “Many details remain unknown about the whistle-blower complaint that is now roiling Washington. But Trump himself has confirmed the core of the story: He pressured the new president of Ukraine to investigate former Vice President Joe Biden, or perhaps to just invent some dirt on him.”

“By all objective standards, this is a monster story. It’s a clear-cut case of not just an impeachable offense, but one that demands impeachment and removal. For a president to invite foreign interference in a U.S. election is a flat-out abuse of power. And that’s not even to mention the widespread suspicion that Trump held up military aid to Ukraine as an added inducement. Just what we know is more than enough; add it to all the other ways in which Trump has violated his oath of office (and see David Leonhardt’s tour de force summation), and it’s not a close call.”

“By all objective standards, that is. Politics, like it or not, isn’t in most cases about objective standards. Which is why on Monday the big test will be very simple: Will Americans light up the phones of their representatives in Congress to demand action? Or is this just more background noise for them – just fodder for partisans to yell about, but nothing more?”

Playbook: “Unlike the Byzantine Russiagate allegations, the latest charge — that the president repeatedly tried to get a foreign leader seeking military aid to investigate a political opponent — is not hard to understand. It’s about the actions of Trump himself, not his aides or former campaign nobodies. At this point, the facts are pretty much in the open and agreed to: The president has practically admitted he discussed Biden with Ukraine’s president, and his lawyer Rudy Giuliani has been open about pressing the Ukrainians to investigate Biden’s son Hunter. Now it’s up to Congress to figure out how to proceed.”

“Speaker Nancy Pelosi understands the caucus’ moods better than anyone, and her letter Sunday — which said the president needs to hand over the whistleblower report now, or else — was a rifle shot that should not be underestimated.”

“Time is of the essence for the Trump White House. If they don’t produce the whistleblower report within days — maybe a week — Democrats are going to be under extreme pressure to move toward impeachment. Thursday will be an important day to watch: That’s when Joseph Maguire, the acting director of national intelligence, is testifying in an open hearing.”

“President Trump acknowledged on Sunday that he raised corruption accusations against former Vice President Joseph R. Biden Jr. during a phone call with Ukraine’s leader, a stunning admission as pressure mounted on Democrats to impeach Mr. Trump over allegations he leaned on a foreign government to help damage a political rival,” the New York Times reports.

“In public and in private, many Democrats said the evidence that has emerged in recent days indicating that Mr. Trump pushed the Ukrainian government to investigate Mr. Biden, and his administration’s stonewalling of attempts by Congress to learn more, were changing their calculations about whether to charge him with articles of impeachment.”

Speaker Nancy Pelosi “called on the Trump administration to promptly turn over a secret whistleblower complaint said to relate to President Trump’s attempts to press Ukraine to investigate his leading Democratic presidential rival, warning that a refusal to do so could force the House to open a new phase in its investigation of him,” the New York Times reports.