It looks like a refresher course is in order on how Congress handles a veto, procedurally and politically.  

It’s been four years and four months since the last time a president rejected a bill that landed on his desk. And 243 House members, along with 54 senators, have taken office since the last time legislation was enacted despite such a veto.  

The most recent veto date (October 2010) is about to be eclipsed, because President Barack Obama has left no doubt he’s going to return the measure approving the Keystone XL oil pipeline. But the most recent override marker (July 2008) is guaranteed to remain a while longer, because neither side of the Capitol has the two-thirds majorities required to make the Keystone bill into a law without the president’s say-so. The House cleared the measure Wednesday afternoon with 270 votes — 19 “yes” ballots away from what would be required to guarantee a veto override. The Senate passed the bill two weeks ago with 62 votes, five shy of the supermajority necessary if every senator answers the call of the roll.  

Those tallies might suggest the suspense has already been drained from the Keystone debate. But, for those who appreciate the interconnectedness of parliamentary maneuvering and political strategizing, a few intriguing twists lie ahead.  

The next act in the showdown is Congress delivering the bill to the White House. Colloquially, people talk of a final vote “sending the bill to the president,” but that’s not exactly so. Before it’s driven downtown, an official copy is printed on parchment and signed by the speaker and Senate president pro tem — and there’s no deadline for this “enrolling” procedure.  

So there’s nothing stopping the Hill leadership from waiting to deliver the Keystone bill, in hopes that something will happen to change the president’s mind. That was the strategy in 1998, when the GOP majorities held on to a bill combining $1 billion in overdue payments to the United Nations with a ban on federal aid to international family planning groups for six months, hoping to win President Bill Clinton’s grudging signature by delivering it just before the midterm elections. (The tactic didn’t work; Clinton’s veto came only hours after the measure arrived.)  

Today’s GOP leaders haven’t talked about such a gambit this time. If they hew to the normal timetable, the Keystone measure will get to the Oval Office early next week and Obama will have 10 days (not counting Sundays) to make his universally expected move. The phrase “veto pen” is also something of a misnomer, because a president actually rejects a bill by returning it to the Hill without his signature — though the Constitution says he must explain his objections, and that’s almost always in the form of a written veto message.  

There’s no requirement Congress consider an override, and for long stretches in history lawmakers didn’t even take a symbolic shot at reversing presidential rebuffs. But of the 14 vetoes so far this century, lawmakers have cast votes on whether to override a dozen — even in cases where the outcome sustaining the president was a totally foregone conclusion.  

That’s what happened with the more recent of Obama’s two vetoes, of a little-noticed bill that would have required notarizations in one state be recognized in other states. He complained it might have facilitated foreclosure fraud, and lawmakers with the mortgage crisis on their minds decided that, in hindsight, they agreed with him. The measure had cleared on a pair of no-objection voice votes, but only 185 House members supported it the second time around.  

The chamber where a vetoed bill originated gets to take the first crack at an override, which means any very-long-odds prospects for the Keystone legislation rest with the Senate. After months of lobbying and three weeks of debate, a unified GOP bloc was joined by nine centrist Democrats on final passage — and there’s no evidence any Democrats are now contemplating changing from “no” to “yes.” An override would require four such switchers and the presence of Sen. Marco Rubio, R-Fla., who was on a presidential fundraising trip when the bill first passed on Jan. 29.  

There are several strategic questions for Senate Majority Leader Mitch McConnell to answer. Do his fellow Republicans look better in the public eye by “fighting the good fight” for job creation but losing their final battle to compel the start of the pipeline’s construction? Or would his side be better off standing pat, because forcing a quixotic override vote would unnecessarily award Obama a high-profile opportunity to boast to the public that he’s won his first big test of wills against an all-GOP Congress?  

The president says Congress shouldn’t be permitted to force his executive hand, and he wants the normal federal-permitting process to decide whether Keystone would exacerbate global warming. But he’s surrounded by advocates portraying the project — an $8 billion, 1,179-mile conduit taking oil extracted from Canada’s tar sands and parts of North Dakota down to Nebraska to connect with existing pipelines to refineries on the Texas Gulf Coast — in much more melodramatic terms. Business groups see a huge burst of economic activity and a boon to energy security, while environmentalists see a climate change accelerant and a mammoth oil spill waiting to happen.  

The hyperbolic nature of this debate , where both sides are deeply dug in, does not create an environment where bipartisan two-thirds majorities might be magically conjured. (Only if there’s a change of heart in the Senate would the pipeline bill ever get another chance in the House.)  

So the Keystone bill looks highly likely to join 96 percent of all the vetoed bills in American history, which died because of the president’s rejection.  

And the last measure in the 4 percent that became law after a veto? It canceled an 11 percent cut in Medicare reimbursements to physicians — another in a long line of usually routine “doc fix” measures. President George W. Bush objected to its financing mechanism, but bipartisan two-thirds majorities in the House and Senate couldn’t have cared less, and they supported the doctors over the lame-duck president from start to finish.  

Related:

Centrist Democrats on McConnell’s List of Potential Collaborators


Senate Absences Begin for 2016


What the Landrieu Adieu Says About the 2015 Senate


Lessons for Lovers of Long-Shelved Budget Reconciliation


The 114th: CQ Roll Call’s Guide to the New Congress


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