Sen. Kamala Harris of California -- the first Senate Democrat to embrace the strategy of rejecting any bill that didn't include protections for DACA recipients -- said it was "foolhardy" to believe McConnell made "any commitment whatsoever."
"Listen, I'm disappointed with a conversation that suggests a false choice: You either fund the government or you take care of these DACA kids," Harris said. "We can do both."
The other three best-known expected 2020 contenders in the Senate -- Sens. Bernie Sanders of Vermont, Elizabeth Warren Massachusetts and Kirsten Gillibrand of New York -- joined Harris among the 18 "no" votes.
The other senator from California, Dianne Feinstein, also said she was "disappointed" with the deal.
In a Democratic caucus meeting, Feinstein complained that she had to vote to shut down the government Friday and asked why the same resolution couldn't have been reached by then, according to a source in the room.
Sen. Jeff Merkley of Oregon voiced objections to the deal, two sources said, raising concerns that the party was giving up too much and would lose support from progressive groups.
Merkley later met with progressive activists who were furious at Schumer and warned they would withhold funding from Democrats in key races, one source said.
"My concern with the three-week extension adopted today is that the Republican leadership will fail to negotiate for 15 of the next 17 days," Merkley said in a statement. "Leader McConnell's track record of keeping his 'commitments' is thin at best."
Democratic votes around the government shutdown have always split between progressives, many of whom are eyeing the 2020 presidential race, and more moderate lawmakers -- particularly the 10 Democrats up for re-election this year in states Trump won in 2016.
Four of those 10 -- Sens. Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Claire McCaskill of Missouri and Joe Donnelly of Indiana -- joined new Sen. Doug Jones of Alabama in casting the five Democratic votes against the shutdown on Friday night and to reopen the government Monday.
Five more Democrats up for re-election this year in Trump-won states voted for the three-week measure Monday. Sen. Jon Tester of Montana was the only Democrat in a Trump-won state who didn't back the deal -- though he said his concern was funding for rural hospitals, rather than immigration.
One of those senators, Ohio's Sherrod Brown, said Democrats "got a good deal."
"McConnell made a pledge in front of the world," Brown said, adding that he is "counting on him" to carry through on his commitment.
But Democrats from bluer, often more diverse states, mindful that Trump set the Obama-era DACA program to end in early March, have supported a strategy of tying their votes for any government funding bill to a permanent solution that allows DACA recipients to remain in the United States. That strategy was overwhelmingly backed by pro-immigration groups and the party's base.
Progressive groups were incensed by the Senate's 81-18 vote Monday to reopen the government at the urging of Senate Minority Leader Chuck Schumer, D-New York.
Asked to describe the left's reaction, Ben Wikler, MoveOn.org's Washington director, responded with one word: "Fury."
"Last week, I was moved to tears of joy when Democrats stood up and fought for progressive values and for Dreamers. Today, I am moved to tears of disappointment and anger that Democrats blinked," said Frank Sharry, executive director of the immigration advocacy group America's Voice.
Other Democratic groups warned that the vote Monday could undercut the party's hopes of taking control of Congress in this year's midterm elections.
"The big blue wave that Schumer hopes will make him Senate majority leader in 2019 will not build itself," said Ezra Levin, a co-executive director of the Indivisible Project, a group that emerged as an organizing hub of the anti-Trump progressive resistance. "Instead, Schumer led his caucus to surrender, demoralizing his base and ensuring more Dreamers will be deported before this is resolved."
"Today's cave by Senate Democrats -- led by weak-kneed, right-of-center Democrats -- is why people don't believe the Democratic Party stands for anything. These weak Democrats hurt the party brand for everyone and make it harder to elect Democrats everywhere in 2018," said Stephanie Taylor, the co-founder of the Progressive Change Campaign Committee, which represents what it calls the "Elizabeth Warren wing" of the party.
"It's official: Chuck Schumer is the worst negotiator in Washington -- even worse than Trump," said CREDO political director Murshed Zaheed.
Zaheed said Schumer was "outmaneuvered" by McConnell and "failed Dreamers and let the entire Democratic Party down."
Progressives in the House responded similarly -- noting that House Speaker Paul Ryan, R-Wisconsin, hasn't matched McConnell's commitments to advance immigration legislation.
Rep. Ro Khanna, D-California, said that without Ryan committing to support DACA and bring it to a vote by February 8, the deal is "meaningless."
"I have no confidence unless Ryan publicly commits to supporting and having a vote on DACA before Feb. 8th," Khanna said in a text message. "Without that commitment progressives around the country and the grassroots of our party will demand we keep fighting for the Dreamers and not settle for a cosmetic deal."
During a House Democratic Caucus meeting, Congressional Black Caucus Chairman Cedric Richmond of Louisiana blamed Schumer for making the whole debate about immigration, according to one Democrat in the meeting, saying about Senate Democrats, "They are getting their butts kicked."