Nancy Pelosi is nothing if not ambitious. The new House Speaker took the unusual step of sending out a letter to House members of both parties urging action to vote on a new bill, a resolution rejecting Donald Trump’s emergency declaration. She’ll need as many Republicans as she can get — not to pass it, but to override Trump’s inevitable veto:

“I write to invite all Members of Congress to cosponsor Congressman Joaquin Castro’s privileged resolution to terminate this emergency declaration,” Pelosi wrote, noting that the House will “move swiftly to pass this bill.”

“The President’s decision to go outside the bounds of the law to try to get what he failed to achieve in the constitutional legislative process violates the Constitution and must be terminated,” she added.

Pelosi sent the letter to both Democrats and Republicans on Wednesday night, a rare occurrence that underscores the seriousness with which the speaker plans to try to block Trump’s effort to go around Congress and build his border wall.

The chances of getting a veto-proof majority on this bill lie somewhere on the spectrum between slim and YGBKM. A few Republicans will undoubtedly cross the aisle to support this bill on constitutional principles, but Pelosi will need 50 or more to override a veto. That’s not going to happen, just as Chuck Schumer isn’t going to find 20 Senate Republicans to cross the aisle in the upper chamber.

Pelosi knows it too, so she has announced that she will authorize a lawsuit blocking Trump from spending money under the declaration. Legal experts don’t think Pelosi has a strong case on this, at least not once appellate courts get involved. Congress has already provided Trump the mechanism for this, which makes the issue of the quality of the emergency a political question that the appellate courts usually leave to the two elective branches:

Harvard Law School Professor Cass Sunstein wrote in a Bloomberg opinion piece last week that courts are not likely to rule that the national emergency is unlawful, even if Trump’s own statements and actions, as well as facts, do not support his declaration.

That’s because under the National Emergencies Act of 1976, Congress gave the president broad power to determine what constitutes a national emergency.

“It’s an emergency under federal law because Trump said it is,” said Jonathan Turley, a George Washington University professor of law and contributor to The Hill. “The National Emergencies Act has one conspicuous omission: It doesn’t define what an emergency is.”

And since Congress gave itself the power to overturn a declaration — by passing a resolution with a simple majority that would require a two-thirds majority to override a veto — the courts may decide the dispute is not for them to decide.

Sunstein’s hardly a conservative stalwart, but he knows how to read the statute and how to interpret Congress’ utter lack of interest in policing it. A challenge in court might end up backfiring on Pelosi, Turley warned, thanks to the timing:

“The odds of Trump prevailing at the Supreme Court are quite high,” Turley said. “That would mean the Democrats may be handing the president a major victory in court right before the voters go to the polls in 2020.”

The Hill notes that Pelosi’s effort will be backed up by lawsuits from sixteen states and a number of public policy groups. True enough, but they may have a big problem establishing standing. Pelosi has the best argument for standing, which is that Trump’s action derogates Congress’ ability to control spending in the federal government. States and public interest groups have no authority over spending, which makes them more likely to be useful in filing amicus briefs.

As for Pelosi’s standing, Congress surrendered it in 1976, as I wrote in my column at The Week:

Unfortunately for Coons and other Democrats — and a handful of Republicans protesting Trump’s actions — that precedent was set decades ago. While this may be the first time a president has used the National Emergencies Act passed by Congress in 1976 to bypass Congress’ appropriations process, the law does indeed contain a grant of authority for presidents to spend money without appropriation from Congress. If Congress challenges Trump’s novel use of the NEA, it might have to explain why the law allows for his move in the first place — and why Congress remained uninterested in policing this authority until now. …

The grant of executive authority in the NEA is not merely ceremonial. The Brennan Center found well over 100 statutory powers that become active for presidents under national emergencies. One in particular speaks directly to Trump’s ambition for a border wall: 10 U.S.C. 2808, which addresses the use of Department of Defense resources. It says that “Secretary of Defense, without regard to any other provision of law, may undertake military construction projects, and may authorize secretaries of the military departments to undertake military construction projects, that are necessary to support such use of the armed forces.” …

If Congress insists on passing the buck to the executive branch, it can’t profess shock and incredulity when a president finally spends it.

This makes it easy for courts to tell Congress that they created this problem, and that its resolution has to be in the political arena rather than in court. Will they? Pelosi et al will likely find circuit court judges to issue favorable temporary injunctions, but once it gets into the appellate levels, these challenges will quickly run out of gas.

Instead of this Stop Trump’s Emergency bill, Pelosi should be pushing a rewrite or repeal of the NEA. Every single member of Congress definitely should sign onto that — and start doing their jobs rather than punting to the executive.

Update: The original omitted a clause in the final sentence of the first paragraph, “as she can get.” I added it back in.