The fatal shooting of a 37-year-old intensive care nurse in Minneapolis on Saturday has upended Congress's plans to fund the government, with Senate Democrats now refusing to support any spending package that includes money for the Department of Homeland Security.

Chuck Schumer made the stakes plain Saturday night. The Senate minority leader said Democrats would block the appropriations bill entirely unless Republicans agree to strip out the $64.4 billion earmarked for DHS—a demand that, if unmet, would trigger a partial government shutdown by Friday.

"What's happening in Minnesota is appalling—and unacceptable in any American city," Schumer said. "Senate Democrats will not provide the votes to proceed to the appropriations bill if the DHS funding bill is included."

The math is unforgiving. Republicans hold 53 seats but need 60 votes to advance spending legislation. That means at least seven Democrats must cross over. As of Sunday evening, more than half the 47-member Democratic caucus had publicly committed to voting no.

Two Weeks, Two Bodies

Alex Pretti died Saturday morning on a Minneapolis street corner. Border Patrol agents said he approached them armed with a 9mm handgun during an immigration enforcement operation and resisted when they tried to disarm him. Pretti held a valid permit for the weapon.

Cellphone footage captured what happened next: agents swarming Pretti, wrestling him to the pavement, then opening fire as he struggled. He was the second person killed by federal immigration officers in the city this month.

On January 7, ICE agent shot Renee Good, a mother of three, after she accelerated her car toward him during an arrest operation. A third man, Julio Cesar Sosa-Celis, was shot in the leg while attempting to evade agents.

The shootings transformed a routine appropriations fight into something far more volatile. Democrats who had been prepared to hold their noses and vote for the DHS bill found themselves facing pressure from colleagues, constituents, and their own consciences to take a harder line.

Patty Murray of Washington, the senior Democrat on the Appropriations Committee, had spent days urging her caucus to support the legislation. Her argument was practical: a shutdown or a stopgap measure would hand the Trump administration even more latitude over how DHS spends its money.

By Saturday night, she had abandoned that position.

"Federal agents cannot murder people in broad daylight and face zero consequences," Murray wrote. "The DHS bill needs to be split off from the larger funding package."

The Defectors

What makes the Democratic revolt significant is who's leading it. Catherine Cortez Masto of Nevada broke with her party last fall to help end the longest government shutdown in American history—43 days of closed agencies and furloughed workers that ended only when a handful of senators crossed the aisle.

Now she's back on the other side.

"The Trump Administration and Kristi Noem are putting undertrained, combative federal agents on the streets with no accountability," Cortez Masto said Saturday. "They are oppressing Americans and are at odds with local law enforcement. This is clearly not about keeping Americans safe."

Jacky Rosen, Nevada's other Democratic senator, followed suit. So did Tim Kaine of Virginia, who said he wouldn't support the DHS bill "without significant amendment." Brian Schatz of Hawaii. Amy Klobuchar and Tina Smith, the two senators from Minnesota. The list kept growing through the weekend.

Adam Schiff of California dispensed with the usual hedging on Sunday morning.

"I'm not giving ICE or border patrol another dime, given how these agencies are operating," he said on NBC. "I think anyone who votes to give them more money to do this will share in the responsibility and see more Americans die in our cities as a result."

A Tangled Package

The procedural reality makes this fight especially difficult to resolve. House Republicans passed the DHS bill last week on a near party-line vote, 220-207, then bundled it with five other appropriations measures covering Defense, Health and Human Services, Labor, State, and several smaller agencies. The combined package landed in the Senate as a single piece of legislation.

Splitting it apart would require the House to vote again—but the House isn't scheduled to be in session this week. The Senate won't convene until Tuesday because a massive winter storm has paralyzed the Northeast. That leaves three days, at most, to avoid a partial shutdown.

Susan Collins of Maine, who chairs the Senate Appropriations Committee, told reporters her staff is "exploring all options." One possibility: passing the five non-DHS bills separately while negotiations continue on homeland security funding. Whether House Republican leaders would accept such an arrangement remains unclear.

Chris Murphy of Connecticut, the top Democrat on the homeland security appropriations subcommittee, laid out what his party wants: warrants for immigration arrests, enhanced training requirements, rules forcing agents to identify themselves, and restrictions keeping Border Patrol focused on the border rather than conducting raids in American cities.

"We cannot fund a department of homeland security that is murdering American citizens, that is traumatizing little boys and girls all across the country in violation of the law," Murphy said Sunday.

Cracks in the GOP

Most Republicans have rallied behind the administration's immigration enforcement push, but the Minneapolis shootings have prompted some to break ranks—at least on the question of accountability.

Bill Cassidy of Louisiana called the events "incredibly disturbing" and demanded a full joint federal and state investigation. "The credibility of ICE and DHS are at stake," he said. "We can trust the American people with the truth."

Thom Tillis of North Carolina warned that officials who "rush to judgment" or try to shut down investigations "are doing an incredible disservice to the nation and to President Trump's legacy."

Others pushed back hard. Lindsey Graham of South Carolina urged Democrats to drop their threat and argued this was "not the time to defund one of our major national security priorities." Bill Hagerty of Tennessee accused Schumer of putting "illegal immigrants above law enforcement."

The White House, for its part, expressed hope that "cooler heads will prevail."

What Comes Next

Senate Democrats huddled on a conference call Sunday evening to plot strategy. Their House counterparts held a separate call earlier in the day with Minnesota Governor Tim Walz and Attorney General Keith Ellison, both former congressmen who represented the state in Washington.

The immediate question is whether Republicans will agree to separate the DHS bill from the rest of the package—and if so, whether that can happen fast enough to beat the Friday deadline. Six of the twelve annual appropriations bills have already become law. The remaining six, bundled together, fund agencies that would face immediate disruption if Congress fails to act.

Schumer framed the choice in stark terms Sunday evening.

"Senate Republicans must work with Democrats to advance the other five funding bills while we work to rewrite the DHS bill," he said. "This is the best course of action."

Government shutdown odds on prediction markets surged past 75 percent over the weekend. The Senate returns Tuesday. The money runs out Friday. And somewhere in Minneapolis, federal agents are still conducting immigration operations while protesters mass in the streets.