As the fourth and final day of confirmation hearings for U.S. Supreme Court nominee Brett Kavanaugh began Friday, advocacy groups that have spent weeks raising alarm about the threat Kavanaugh poses to Americans' human and civil rights urged constituents to contact their senators and continued to #WhipTheVote in the absence of strong leadership from Senate Minority Leader Chuck Schumer (D-N.Y.).

"Since Schumer won't #WhipTheVote to #StopKavanaugh," Indivisible declared, "we will."

Frustrated by Schumer's refusual to pressure Democratic lawmakers to unite in opposition to President Donald Trump's deeply unpopular nominee, 13 organizations this week called out the Senate's top Democrat in a fierce letter that stated, "The Supreme Court is on the line, and you are failing us." Indivisible, one of the signatories, has followed up with tweets urging voters to keep the pressure on their elected officials:

Several of the groups that signed the letter to Schumer, and others, are tracking all senators' positions on Kavanaugh's confirmation at WhipTheVote.org.

Among the 19 Democrats classified as "on the fence," WhipTheVote.org documents five as "neutral"—Sens. Joe Donnelly, (Ind.), Heidi Heitkamp (N.D.), Doug Jones (Ala.), Joe Manchin (W.Va.), and Claire McCaskill (Mo.)—and 14 others as "lean oppose."

Including Sen. Angus King, the Independent from Maine who caucuses with the Democrats, the legislators who "lean oppose" are Sens. Michael Bennet (D-Colo.), Chris Coons (D-Del.), Catherine Cortez Mastro (D-Nev.), Dick Durbin (D-Ill.), Dianne Feinstein (D-Calif.), Maggie Hassan (D-N.H.), Tim Kaine (D-Va.), Patrick Leahy (D-Vt.), Bill Nelson (D-Fla.), Jeanne Shaheen (D-N.H.), Jon Tester (D-Mt.), Mark Warner (D-Va.), and Sheldon Whitehouse (D-R.I.).

Sens. Lisa Murkoski of Alaska and Susan Collins of Maine, the two Republicans believed most likely to succumb to pressure and vote against Kavanaugh, are also designated as "neutral."

A corresponding Twitter account has kept followers updated as lawmakers have made public statements throughout this week's closely watched and hotly contested hearings. After a representative for Sen. Maria Cantwell (D-Wash.) confirmed to a reporter on Thursday that she will vote "no," the account praised her position while also emphasizing that "we need all Democratic senators to unite in opposition to Trump's Supreme Court nominee."

Thank you, @SenatorCantwell for voting NO on Kavanaugh! We need all Democratic senators to unite in opposition to Trump’s Supreme Court nominee. Check and see where your senator stands at https://t.co/piR1ikhZ88 #StopKavanaugh #WhipTheVote https://t.co/EXBqsE5V4u SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— #StopKavanaugh (@WeDemandJustice) September 6, 2018

Thanking Sen. Ben Cardin (D-Md.) for tweeting on Friday that he, too, plans to oppose Kavanaugh in the final vote, the account also pointed to the 19 Senate Democrats who remain "on the fence," and encouraged voters to flood their offices with calls.

And thank YOU, @SenatorCardin! We still have 19 Democrats on the fence. See where your senator stands at https://t.co/qi0vGfweRf and give ‘em a call at 1-855-765-1382. #WhipTheVote https://t.co/MPqRfvz6mn — #StopKavanaugh (@WeDemandJustice) September 7, 2018

In a series of tweets Friday morning, Cardin called on his Senate colleagues to oppose the far-right, business-friendly judge, charging that "any reasonable person would have cause to be concerned, even fearful, of his confirmation to the Supreme Court," especially considering: "1) his judicial track record 2) his equivocation on whether presidents should be investigated while in office, even though he investigated President Bill Clinton for Independent Counsel Ken Starr, and 3) what little we have seen of his White House record."

"Any reasonable person would have cause to be concerned, even fearful, of his confirmation to the Supreme Court."

—Sen. Ben Cardin

Cardin also decried the "outrageous" confirmation process—including a massive document dump the night before the hearings that he called "an especially egregious display of contempt for the constitutional process." He concluded that the Trump administration and Republicans lawmakers' efforts to conceal the bulk of Kavanaugh's record represent "a turning point in American history."

The hearings—which Republican leaders have refused to delay despite complaints from Democrats over documents that have been withheld from lawmakers and the public regarding Kavanaugh's record—have provoked unprecedented protests across the nation and within the Capitol Building, with more than 200 demonstrators arrested by Capitol Police over the past three days. The protests continued on Friday.