Plenty of Democrats, and even some Republicans, say they are opposed to President Donald Trump’s declaration of a national emergency, an extraordinary step that could divert billions of dollars in funding from other federal projects to his much-touted border wall.

But even states led by Democrats appear to be split on whether there’s anything they can do about it, at least for now. That became clear Monday, when 16 states, most led by Democrats — including California, New Jersey and Delaware — filed a lawsuit seeking to block Trump’s order.

Notably absent from the suit was Pennsylvania, where Attorney General Josh Shapiro, a Democrat, says he’s waiting to see whether Trump will take money that had been appropriated for projects in the commonwealth. Ten other Democratic attorneys general, including those in Massachusetts and Washington, are also holding off on litigation.

“I need to understand better where the money is coming from, whether or not it’s going to be taken from the people of Pennsylvania, the taxpayers,” Shapiro said Tuesday. “I don’t have that information yet. So when I go to court to defend the interests of Pennsylvanians, I want to have the strongest possible case.”

The states’ pondering of their own legal authority comes as Trump asserts an expansive view of executive power, saying he has emergency authority over spending that is delegated to Congress by the Constitution.

The White House says it has identified $8.1 billion available for a border wall, including funding previously appropriated for military construction projects and activities to counter drug trafficking. Of that, Congress allocated $1.375 billion for border fencing.

Trump has argued that the wall is needed for national security, though government data show border apprehensions fell to the lowest level in more than 45 years in fiscal year 2017, and most drugs smuggled into the U.S. come through legal points of entry.

There are six military construction projects in Pennsylvania, totaling $164 million, from which Trump could seek to divert funds, according to data provided by the House Appropriations Committee. That includes $71 million for a Navy propulsor manufacturing support facility in Philadelphia.

The lawsuit alleges Trump would violate the Constitution’s separation of powers by redirecting federal dollars even after Congress specifically rejected his request for more wall funding. The states say they have standing — a legal threshold to initiate a lawsuit — because they would lose federal funding and, in the case of California and New Mexico, face “irreparable environmental damages.”

Courts in recent years have increasingly recognized states’ authority to challenge the federal government even in cases that don’t directly affect state law, said Tara Leigh Grove, a constitutional law professor at William and Mary Law School.

That traces back to a 2007 U.S. Supreme Court decision that found Massachusetts could sue the federal government for its failure to regulate greenhouse gas emissions.

During the Obama administration, an appeals court ruled in 2014 that Texas and 25 other states had standing to sue the president for allegedly failing to enforce federal immigration law with his program granting protected status for certain undocumented immigrants.

Likewise, Grove said that with regard to Trump’s national emergency declaration, “I think there’s a very good chance a court will find many of these states have standing.”

“We haven’t had a case like this before,” she said.

In Washington, Congress could try to reject the president’s emergency declaration with a resolution of disapproval, though it’s unlikely lawmakers would have a veto-proof majority.

Groups like the American Civil Liberties Union have also filed suit.

Shapiro hasn’t been shy about challenging the Trump administration on everything from the rollback of environmental regulations to the rescinding of Obama-era protections for undocumented immigrants.

But Shapiro has declined to join some high-profile cases. For example, after he and other state attorneys general successfully blocked Trump’s first travel ban, Shapiro opted not to be a party in subsequent lawsuits that challenged revised versions of the ban. The U.S. Supreme Court ultimately upheld a revised ban.

Republicans have suggested Pennsylvania’s attorney general is trying to build his profile amid a possible run for governor in 2022.

When Shapiro went before state lawmakers in Harrisburg last week for a budget hearing, Rep. Doyle Heffley (R., Carbon) accused him of picking fights with Trump for political gain.

“If I were to sue the president every time I had a policy difference from him, I’d have sued him a thousand times already,” Shapiro responded, adding that he makes such decisions based on the rule of law. “I haven’t. I’ve sued him 22 times. Eleven have gone to court, and I’m 11-0.”

Speaking to reporters in the Capitol on Tuesday, Gov. Tom Wolf, a Democrat, said he spoke with Shapiro several times on Monday in an effort to assess how — and whether — Pennsylvania will be impacted by the president’s emergency order.

“He’s trying to be very responsible,” Wolf said of Shapiro, “and make sure that he can show that Pennsylvania actually has a stake in this suit.”

Officials in states like Washington, where Democratic Gov. Jay Inslee is considering a run for president, also say they want to know where Trump plans to siphon money before filing a lawsuit.

New Jersey Attorney General Gurbir S. Grewal has joined the lawsuit, which says the Garden State would lose federal funding for military construction projects and counter-narcotics activity.

Reached for comment, his office would not identify which specific projects would lose funding. The House Appropriations Committee identified about $51 million in funding for military construction projects in New Jersey that could potentially go to Trump’s wall, including $10.2 million for Joint Base McGuire-Dix-Lakehurst.

Grewal told NPR Tuesday that he would use the litigation to find “where exactly the administration is seeking to go to raid those funds.”

“When we take action against the administration, we ask ourselves two questions,” Grewal said. “Is what they’re doing unlawful? And, two, does it affect New Jersey?”

Staff writers Jonathan Tamari, Angela Couloumbis, and Chris Brennan contributed to this article.