With the Republicans now in control of both houses of Congress, President Barack Obama has finally invoked his weapon of last resort against being run over by them, by vetoing the Keystone XL pipeline bill.
After more than six years in office and having used the veto only twice before on procedural matters, Mr. Obama has dug it out to show his party's liberal wing that he is still faithful to it — at least on the issues of environmental protection and climate change.
Technically, Mr. Obama based the latest veto on grounds the State Department has not completed its required review of the environmental and other impacts of the pipeline. Democratic Sen. Ed Markey of Massachusetts is quoted by Politico saying it would allow "some of the dirtiest oil in the world to be funneled through our country like a straw."
But more significantly political than the pipeline itself is the message Mr. Obama has sent to fellow Democrats — that he is finished at last turning the other cheek to the congressional GOP's obstructionism that has frustrated his own domestic agenda from the start. Whether he holds to that message remains an open question.
The principal catalyst for Mr. Obama's resort to his veto power is the November loss of the U.S. Senate, and the consequent demotion of Sen. Harry Reid from majority to minority leader. Mr. Reid is now denied his previous ability to reject legislation from the House Republican majority. He can, however, still thwart the opposition party by denying it the 60 votes required to cut off Senate debate on a range of issues.
The 54 Senate votes now in the hands of new Majority Leader Mitch McConnell enabled Republicans to pass the Keystone pipeline. But he does not have the two-thirds required to override any Obama veto, more of which are likely to come as the president digs in his heels for a stormy last 22 months in office.
In refusing to sign onto construction of the pipeline, Mr. Obama is holding his ground on his plan to halt deportation of up the 5 million alien immigrants, which the Republicans sought to block as ransom for passage of Keystone. Mr. McConnell's offer to allow a clean vote on the Department of Homeland Security budget that would avert a shutdown of the agency was shunted off to House Speaker John Boehner, leaving in question whether his conservative and tea-party caucus would cooperate.
In this continuing maneuvering on Capitol Hill, Mr. Obama has succeeded in putting the ball back on the Republicans' court, highlighting Mr. Boehner's continuing challenge to cope with a fractious House caucus. The speaker has been insisting the Senate Democrats have to break the impasse by voting for the pipeline with the GOP caveat against the Obama immigration reform attached.
The president's resort to issuing an executive order on the deportation issue — his answer to the years-long strategy of obstruction against him — figures to be the pattern for political jockeying through the remaining Obama White House years.
It has already inspired conservative and tea party Republicans to talk of impeachment proceedings against him on grounds of failure to enforce the nation's laws by going around them via such executive orders.
Also, a Texas District Court judge has put a temporary stay on the Obama executive order deportations in a case arguing that it is unconstitutional. The administration is appealing, an action that could bring the issue before the Supreme Court.
In a sense, Mr. Obama's ability to get anything much done domestically in his time left in office may ride on the outcome. Meanwhile, his plate remains full with grim foreign-policy challenges, from the Middle East to Ukraine, relief from which not even his veto pen can offer an escape hatch.
He could not be faulted were he to reflect longingly on FDR's two daring if failed schemes — to pack a Supreme Court unfriendly to his New Deal agenda, and later to purge through the election process uncooperative members of Congress. Instead, Mr. Obama has to hope for changes of heart and conviction in both the court and Congress, not likely to occur in either place in the current political climate.
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is firstname.lastname@example.org.