If Republicans gain control of the Senate, what will that mean for the last two years of the Obama administration?

As young people often say about their relationships on Facebook: It’s complicated.

On the legislation front, gridlock is likely to persist, and could get worse. Obama, whose agenda is already stymied, would be playing defense most of the time instead of offense.

Since Republicans would need 60 votes in the Senate to overcome a filibuster and 67 to override a veto, their ability to enact their own agenda would be severely limited, as well.

Elections always have consequences, however, and legislation is not the only way to measure their impact. If Republicans seize the Senate, they would set the floor schedule and run the committees. Republican staffs would grow while Democratic ranks shrink. The GOP would be able to hold hearings, summon witnesses, raise questions, shine spotlights, investigate problems and apply pressure.

House Republicans are already using their majority status to scrutinize the administration on issues ranging from the Internal Revenue Service to the Veterans Affairs department. A select committee probing the Benghazi affair waits in the wings. A Republican Senate, bristling with ambitious new committee chairmen, would only compound the administration’s misery.

One example: John McCain, in line to head the Armed Services Committee, has harshly criticized the president’s military responses to a wide range of challenges. The Arizona senator, writes the Associated Press, “would be certain to use his new perch for tough questioning about Iraq, Syria, Iran, Afghanistan and military spending.”

The GOP’s greatest leverage, however, would be over appointments requiring Senate confirmation. That starts with the successor to Attorney General Eric Holder, who’s announced his resignation, and includes a variety of ambassadors, commissioners and lower level cabinet officers.

“Anyone thinking about moving to Washington to wait for a presidential appointment and confirmation ought to think twice,” professor Paul Light of NYU, an expert on presidential personnel, told the McClatchy newspapers.

An even bigger issue would be federal judgeships, lifetime jobs that often comprise a major part of a president’s legacy. There are currently 63 judicial vacancies and 32 pending nominations. Few of those candidates could win the approval of a Republican Senate.

Probably the most closely watched person in Washington next year would be Justice Ruth Bader Ginsburg, who turns 82 in March and has suffered at least two bouts with cancer. The justice belongs to a four-member liberal bloc that balances four conservatives, with Justice Anthony Kennedy often serving as the swing vote. Ginsburg’s departure — either voluntarily or for health reasons — would set off the single biggest battle of Obama’s final two years.

A gloomy picture all around. Still, there’s a small possibility that if Republicans take the Senate, they will be motivated to work with the president and prove they can govern.

Hopes for that kind of bipartisan bonding have been dashed repeatedly in recent years, but history provides a few encouraging examples. After Republicans took control of the House in 1994, for instance, they worked with President Clinton to pass major welfare reforms.

If that dynamic kicks in, a short list of legislative measures could make progress. Many Republicans favor giving the president expanded powers to push global trade agreements through Congress. The Democratic leader in the Senate, Harry Reid,  has been bowing to pressure from labor and opposing the idea. A Republican Senate could actually help the president on that one.

A number of Democrats could join with Republicans in extending the Keystone XL pipeline, which brings crude oil from Canada to U.S. refineries. Tax reform focusing on corporations would be another possibility.

The more likely outcome is that Republican leaders would try to crush the Democrats instead of cooperate with them. Mitch McConnell — who would run the Senate if he survives his re-election bid and Republicans take the majority — has talked candidly about using the annual spending bills that fund the government to put the president in a tough spot.

His idea: Attach amendments to those bills that restrict the president’s ability to spend money implementing, say, environmental regulations or Obamacare. If the president signs the bills, he accepts Republican policies; if he vetoes them, he risks shutting down the government.

All second-term presidents suffer from dwindling clout and capital. But as Gene Healy, vice president of the Cato Institute, told the Washington Times, when the opposing party controls the Congress, life in the White House “tends to be even less fun than usual.”

The Robertses can be contacted at stevecokie@gmail.com.