Democratic leadership says we're in a constitutional crisis — so why won't they call for the obvious solution?

With support for President Donald Trump's impeachment surging among the American public—as evidenced by new polling data and the 10 million petition signatures delivered to Congress on Thursday—House Democratic leaders are facing growing pressure to take action in line with their ominous warnings that the U.S. is in the midst of a "constitutional crisis."

A new Reuters/Ipsos survey published Thursday showed that support for impeaching Trump has risen to 45 percent, up five points since mid-April—which is around when the redacted Mueller report was made public.

Shortly following the new polling data, Michelle Goldberg of the New York Times used her Friday column to send a straightforward message to the Democratic leadership: "If this is a constitutional crisis, act like it."

"[H]owever you define constitutional crisis, there's no question we're in a moment of constitutional hardball," Goldberg wrote. "So far, however, only Republicans really seem to be playing."

Goldberg's column was published shortly after House Speaker Nancy Pelosi (D-Calif.) said the Trump administration's lawlessness has sparked a constitutional crisis, echoing House Judiciary Committee chairman's declaration from a day earlier.

Despite this grave warning, Goldberg noted, Pelosi "repeated the Democratic refrain that the House needs to engage in further investigation rather than impeachment."

"But it is incoherent to argue that Trump constitutes an existential threat to the Constitution, and that Congress should wait to use the Constitution's primary defense against such a threat," Goldberg argued. "There are dangers in increased Democratic combativeness, but even greater dangers in timidity."

Goldberg's call for Democrats to take bold action to combat the constitutional threats posed by the Trump administration has been echoed by other commentators in recent days, as the White House continues to defy congressional subpoenas for the unredacted Mueller report, the underlying evidence behind the special counsel's 400-page report, and the president's tax returns.

The Week's Ryan Cooper argued in a column Thursday that "Trump has unquestionably committed impeachable acts," from obstruction of justice to maintaining his "vast business empire while in office."

Therefore, wrote Cooper, "impeachment is constitutionally obligated."

"The separation of powers only works if the other branches actually defend their prerogatives. Every one of the Founding Fathers would be horrified that this corrupt, incompetent oaf is still in office," Cooper concluded. "Retreating into learned helplessness and hoping the voters will rescue the country from Trump will only embolden his assault on American democracy."

As grassroots advocacy groups showed with their rally in front of the U.S. Capitol Building on Thursday, members of the media are far from the only ones calling on Democrats to uphold their constitutional duty by launching impeachment proceedings against Trump.

"We agree with Speaker Pelosi: We are in a constitutional crisis. And there is a remedy: Start impeachment hearings now," said Jane Slusser of Need to Impeach, part of the coalition that delivered 10 million petition signatures urging House Democrats to immediately begin impeachment hearings.

While much of the Democratic leadership continues to sidestep or dismiss the impeachment question, Sen. Elizabeth Warren (D-Mass.)—a 2020 presidential candidate—made a powerful case for impeaching Trump on the floor of the Senate this week.

"Mueller served up the evidence on a silver platter to Congress. Congress is now the only body that can act to prevent a president from obstructing justice and walking away with no penalty imposed," Warren said. "I had never intended this to be any part of my presidential campaign. I'm running on how to make this government work."

"Every single person in the House and the Senate should take a vote on whether what Donald Trump did to obstruct justice was an impeachable offense," Warren declared. "And then they ought to have to live with that vote for the rest of their lives."

When reporters asked the Massachusetts senator about the reluctance of other members of the Democratic caucus to back calls for impeachment hearings, she said, "I just don't get it."

Watch Warren's full floor speech: