In a demonstration of mounting crisis within the US political system, the Senate voted Thursday afternoon, by a margin of 59-41, for a resolution to overturn the declaration of national emergency issued by President Trump on February 15, in which he directed military resources to be used for the building of a wall along the US-Mexico border.

Twelve Republican senators broke with Trump on the issue, joining all 47 Democrats to approve the resolution adopted by the House of Representatives on February 26. Under the terms of the 1976 National Emergencies Act, the passage of a resolution by either house of Congress to overturn a presidential declaration of emergency forces the other house to vote on the issue within 18 days. No filibusters or other procedural delays are permitted, and the vote is by a simple majority.

Trump is expected to veto the resolution as soon as it is delivered to his desk. He tweeted the single word “VETO!” within minutes of the Senate vote. His twitter feed Thursday was filled with invective against the Democrats and House Speaker Nancy Pelosi, and he threatened political retaliation against any Republican senator who defied the White House.

That 12 Republicans defied such threats is significant. The previous day, seven Republicans broke with the White House to vote in favor of a resolution condemning US support for the military intervention by Saudi Arabia in the civil war in Yemen, enabling passage of the resolution by a 54-46 margin.

More important than these rebuffs, however, are 41 Senate Republicans who voted in support of the White House on the national emergency declaration. The vast majority of the Republican caucus thus sanctioned presidential actions that brazenly breach the separation of powers laid down in the US Constitution. They would not uphold the most important power of their own institution, the exclusive authority to appropriate funds, and thereby provide the resources to carry out federal action.

The Republicans who voted in favor of the resolution of disapproval made it clear that they actually support Trump’s policy of savage repression of immigrants, including the building of a border wall. Their objection was to the unconstitutional methods employed: issuing an emergency declaration after Congress had refused to provide more than $1.375 billion for “border security,” with a specific prohibition on building more than 55 miles of new wall.

“I believe the use of emergency powers in this circumstance violates the Constitution,” said Senator Jerry Moran, a conservative Republican from Kansas, in a hand-written statement. “This continues our country down the path of all-powerful executive—something those who wrote the Constitution were fearful of.”

Senator Lamar Alexander of Tennessee, who earlier warned Trump was provoking a “constitutional crisis,” observed, “Never before has a president asked for funding, Congress has not provided it, and the president then has used the National Emergencies Act of 1976 to spend the money anyway.”

Senator Mitt Romney of Utah, the Republican presidential candidate in 2012, described the resolution as “a vote for the Constitution and for the balance of powers that is at its core.” He added, “I am seriously concerned that overreach by the Executive Branch is an invitation to further expansion and abuse by future presidents.”

Many senators embraced this argument: that Trump was setting a precedent for a future Democratic chief executive who might claim climate change or gun violence constituted a “national emergency” and take unilateral action without congressional sanction.

Trump’s response to this, delivered earlier this month at the Conservative Political Action Conference, is worth noting. He said the best way to prevent a Democratic president from declaring such emergencies was to win the 2020 election. And not only 2020: the only context in which his rejoinder makes sense is as part of a perspective of maintaining an ultra-right grip on the White House more or less indefinitely.

Throughout the confrontation between the White House and congressional Democrats, which has now extended for nearly three months, since Trump reneged on a bipartisan budget deal and forced a partial shutdown of the federal government in late December, Trump has operated outside the normal rules of American bourgeois politics.

· In December, Trump rejected the continuing resolution devised by Senate Majority Leader Mitch McConnell to provide time to negotiate a longer-term bipartisan budget deal.

· He allowed the shutdown to continue for 35 days, until faced with the danger of a mass refusal to work by federal workers who were going without pay.

· After accepting a short-term continuing resolution, and then a deal that limited border security funding to $1.375 billion, the same figure proposed in December, Trump issued his declaration of national emergency, proposing to shift funds from various Pentagon accounts to the Department of Homeland Security, in direct violation of decisions by the legislature.

· In the run-up to the Senate vote, Trump twice blocked efforts by Senate Republicans to find a legislative end-run around the constitutional conflict.

· Now, faced with the unprecedented action by both houses of Congress repudiating his declaration of a national emergency, Trump will veto the resolution and rely on an ultra-right minority in the House of Representatives to uphold his veto.

Throughout this period, Trump has sought to whip up his ultra-right base with open appeals to racism and anti-immigrant bigotry and fascistic attacks on socialism, as in his notorious declaration in the State of the Union address that he would never let America become a socialist country.

The Democratic Party leadership and its supporters in the corporate media are celebrating the Senate vote as a serious rebuke to Trump, and even as a turning point in American politics. “I’m thankful that Republican senators did the right thing,” Senate Minority Leader Chuck Schumer said. “Let’s hope that these votes this week are green shoots. Republicans, out of courage, out of principle and maybe out of exasperation, are beginning to constrain the president when he goes too far.”

More significant than the Senate vote, however, is the declaration Monday by House Speaker Nancy Pelosi that impeachment of Trump is not on her political agenda.

Those Senate Republicans who voted against Trump’s declaration of a national emergency emphasized that the president was violating the Constitution. Pelosi herself, in a letter sent out to the members of the House last month, declared, “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.”

But Pelosi rejects the constitutional mechanism for removal of a president who systematically violates the Constitution. In fact, neither Pelosi nor any other congressional Democrat—including those who claim to support impeachment—have cited Trump’s brazen violation of the Constitution through the emergency declaration as grounds for his removal from office.

Not one congressional Democrat is calling for demonstrations or mass protests against Trump’s violation of the Constitution. On the contrary, the main concern of Pelosi & Co. is that the conflict within the ruling elite is weakening the authority of the capitalist state, under conditions of a rising movement of working class militancy and opposition to both corporate-controlled parties, expressed in strikes by teachers and industrial and service workers.