The partial government shutdown, now in its record-setting 24th day, is about more than just a wall along the U.S.-Mexico border.

Democrats and their allies are concerned that if party leaders cut a deal with President Donald Trump on wall funding, it would set a precedent for more rounds of dangerous brinksmanship in the months and years to come.

“If this shutdown that’s been initiated by the president works as a tactic to get a portion of his wall, he’ll do it next time,” Sen. Angus King of Maine, an independent who caucuses with the Democrats, said Friday on the Senate floor. “That’s why the age-old principle is you don’t negotiate with hostage-takers. Why? Because if you do, the next time they’ll do it again.”

Rep. Lucille Roybal-Allard, D-California, who will likely write the next Homeland Security appropriations bill in her chamber, said she “absolutely” expects Trump would trigger additional shutdowns as a bargaining chip if Democrats make a deal with him on wall funding now.

Watch: It’s official – longest shutdown ever

A unified Democratic front in the border fight could also help bolster their hand in upcoming negotiations to avoid a steep decline in domestic appropriations over the next two fiscal years.

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Democrats want to ensure equal treatment for both defense and non-defense programs, which would otherwise be slashed by 11 percent and 9 percent respectively when fiscal 2020 begins on Oct. 1. Those limits would rise slightly the following year, but would still be well below were they were in fiscal 2018 without Trump’s signature on a new law overriding the old numbers.

And Trump has already sent signals that his administration is preparing to propose dramatic cuts in domestic and foreign aid programs in his fiscal 2020 budget request, while potentially increasing defense spending by nearly 5 percent.

Democrats are also digging in on government funding in part because lawmakers have a more dangerous fiscal deadline ahead — raising or suspending the nation’s borrowing cap — where they could find themselves with a weaker negotiating hand.

‘Even bigger disaster’

While a partial shutdown has serious repercussions, failure to address the debt ceiling would be much worse.

It would limit what Treasury can spend on all government obligations — from Social Security checks to military paychecks to interest payments on the debt — to the amount of money coming in each day, which would run dry fast. Treasury debt could lose its status as the safest, most liquid asset for global investors, threatening the pristine U.S. credit rating.

“The debt ceiling is potentially an even bigger disaster,” said Seth Hanlon, a senior fellow at the liberal-leaning Center for American Progress. “So, I think, the lesson from this is that Democrats aren’t going to give in to extortion. They’ve had that view in past debt ceiling fights and after 2011, Democrats made it pretty clear they weren’t going to give in to taking the debt ceiling as hostage.”

The most recent debt limit suspension will expire on March 1, but Treasury Secretary Steven Mnuchin is expected to use accounting maneuvers to allow the U.S. to continue borrowing for several more months. The real deadline is expected sometime in late summer, though Treasury has to continually evaluate the inflow and outflow of federal revenue.

In 2011, the U.S. came close to defaulting as negotiations over how to reduce the rising national debt led to a months long stalemate between the Obama administration and a divided Congress. Then-Treasury Secretary Timothy Geithner wrote to lawmakers in May to tell them to find a solution before Aug. 2, otherwise “the borrowing authority of the United States will be exhausted.”

A deal wasn’t reached until late July, and the 2011 law trimming an estimated $2.1 trillion from deficits over a decade passed the House on Aug. 1, the Senate on Aug. 2 and was signed by President Barack Obama almost immediately. Democrats pressed for revenue increases to be in the deal, but ultimately only spending was cut, though Obama was able to ensure defense dollars were affected, not just domestic programs.

But the then-majority House Republicans still proved immovable on some issues, triggering another lengthy shutdown of 16 days in 2013 when Obama wouldn’t agree to defund his health care law.

To critics, Trump’s general lack of experience in governing and his unconventional style as a politician is causing concern that he may view the debt limit as another bargaining tactic — especially if he gets what he wants out of the shutdown.

“The problem is you have an irrational actor,” Hanlon said. “I hope to God he learns the right lesson from this, which is he won’t get what he wants from taking the American people and the American economy hostage.”

It takes two

After weeks of unsuccessful negotiations and missed paychecks for 800,000 federal employees, the two sides appear no closer to achieving a compromise that would reopen the nine Cabinet departments and dozens of other agencies shuttered since Dec. 22.

For Republicans, even those queasy about the idea of shutting down agencies that have nothing to do with border security, the issue is that the Democrats aren’t showing any willingness to bend.

Sen. Susan Collins, R-Maine, has repeatedly urged her party leadership to reopen other portions of the government, calling out Trump in particular. But she’s also taken Democrats to task, saying she was “disappointed” in the position taken by House Speaker Nancy Pelosi of California of “not one penny” for wall funding.

Sen. Lindsey Graham, R-South Carolina, has repeatedly urged a compromise that would provide the wall money that Trump wants while giving the Democrats the liberalized immigration policies they want. But Graham, who vied with Trump for his party’s 2016 presidential nomination — earning Trump’s ridicule in the process — says he’s fed up with the Democrats.

Graham released a blistering statement Friday after meeting with Trump, urging the president to simply declare an emergency at the border and bypass Congress to build his wall.

“It’s clear to both of us that Democrats don’t want to make a deal and will never support border wall/barriers on President Trump’s watch,” Graham said. “They hate President Trump more than they want to fix problems — even problems they acknowledged to be real and serious in the past. Democrats will do everything in their power to defeat Trump in 2020.”

Kellie Mejdrich contributed to this report.