WASHINGTON – Among the direct political implications for Washington politics, for state houses and kitchen tables across the US, Tuesday’s midterm elections marked the beginning of the end for President Barack Obama’s political career.The president enters his final two years in office having just begun a military campaign against a terrorist organization larger than any other in history, with no definitive end in sight. He hopes to clinch a comprehensive deal with Iran and other world powers over its nuclear program that is acceptable to the Israeli government. And, like two US presidents before him, he seeks to restart stalled efforts toward peace between Israel and the Palestinians – or at least to prevent their definitive end.The White House on Tuesday remained relatively quiet. The president remained in the West Wing for meetings on the country’s responses to the Ebola virus and to Islamic State.He declined to campaign in Senate races being hotly contested, from Iowa, whose people might elect their first woman to statewide office, to Kansas, where an independent could straddle the balance of power in the Senate, likely to tip into Republican control.After clinching victory, Mitch McConnell (R-Kentucky) will lead the upper chamber as majority leader. And in that position, McConnell has promised change from Capitol Hill.With both houses under unified leadership, the president can expect bills to arrive on his desk that were long blocked from debate or vote by a Democratic majority leader.Productivity will be an imperative for McConnell, whose party will immediately pivot to focus on the 2016 presidential election. Republicans will seek to appear productive during their two years in control of the legislature before that time.The Democratic presidential race will begin shortly after the midterm votes are counted. Former secretary of state Hillary Clinton, front-runner for her party’s nomination in 2016, says she expects to announce in January whether she will run.Whether Obama can arrive at a compromise with a Republican Congress on significant issues – moderate fixes to healthcare reform, a comprehensive immigration bill, sufficient standards in dealing with Iran – will be the greatest question challenging the remainder of his presidency. But regardless of Republican successes on Tuesday, the clock will begin its countdown on the president’s final days in office.