Barack Obama was reelected for a second term as US President. Credit: JEWEL SAMAD/AFP/Getty Images

A long and contentious election campaign culminated in a decisive victory for US president Barack Obama, who cemented a second term in the White House by beating back Republican challenger Mitt Romney in key battleground states including Ohio, Virginia, Wisconsin and Colorado.

Although vote-counting continued late into the night, major media outlets called the election well before midnight on the east coast as one swing state after another lined up in the Democratic column. The 6 November victory will give Obama and his celebrated science dream team another four years to advance a vision that puts science at the centre of US innovation and competitiveness (see 'The Obama Experiment').

“We want our kids to grow up in a country where they have access to the best schools and the best teachers, a country that lives up to its legacy as the global leader in technology and discovery and innovation,” Obama said during an energized acceptance speech in Chicago, Illinois. “We want our children to live in an America that isn’t burdened by debt, that isn’t weakened by inequality, that isn’t threatened by the destructive power of a warming planet.”

The drama kicked off early in the evening as major media outlets called Pennsylvania in Obama’s favour, and then Wisconsin. Both states went for Obama in 2008, but the Romney campaign had hoped to capture at least one of them in this year's contest. The momentum continued in Obama’s favour throughout the evening. By 11:20 p.m. Eastern Standard Time, the major networks had called Ohio, one of the main battlegrounds, and many went on to call the election minutes later.

By 2:15 a.m., Obama had secured 303 votes within the state-based Electoral College, well surpassing the 270 votes he needed to claim victory. Only Florida, with its 29 electoral votes, remained a toss-up, but there, too, Obama held a slight, 1%, lead over Romney, with 99% of the votes counted. Obama also maintained a narrow lead in the popular vote, which stood at 50% to 49% as of 3 a.m.. 

Romney conceded the election in a speech from his campaign headquarters in Boston, Massachusetts. “This is a time of great challenges for America,” Romney said, “and I pray that the president will be successful in guiding our nation.”

Republicans went into the elections with 240 seats in the House of Representatives, compared with 190 for the Democrats. A number of congressional races remain, but Republicans are projected to retain control over the House of Representatives by a similar margin. By 3:00 a.m., Republicans had secured 224 seats to the Democrats’ 171. (218 seats secures a majority.)

A similar story played out with Democrats in the Senate. By 3 a.m., the Democrats had secured narrow control, with 52 seats to the Republicans' 44, with one independent and three seats outstanding. In Massachusetts, Democratic Senate candidate Elizabeth Warren defeated Republican Senator Scott Brown in one of the most important Senate races. In Florida, two-term Democrat senator and long-time NASA supporter Bill Nelson defeated Republican challenger Connie Mack, and Missouri Democrat Claire McCaskill, a long-time stem-cell champion, won re-election against Republican Todd Akin. In Illinois, Democrat Bill Foster, a high-energy physicist and a former House representative, regained the seat he lost in 2010.

Big wind

Although the presidential campaign focused on the economy, Obama made science and education cornerstones of his long-term vision for the country. Both candidates emphasized the need to boost domestic energy production and reduce the United States’ reliance on foreign oil, but they differed in several important respects. Whereas Obama underscored cleaner-burning natural gas and the need to continue support for renewable energy, Romney questioned federal subsidies for renewables and promoted any and all domestic fossil fuels, including coal.

Until Hurricane Sandy roared into the coast last week, global warming had arisen only in the context of a political debate over government regulation. Romney advanced the widespread conservative opposition to regulations of any kind, arguing that they are stifling economic growth. That position drew fire from New York City Mayor Michael Bloomberg, who, as his city struggled to recover from Sandy, cited the need for action on global warming and weighed in with a last-minute endorsement of Obama. Building on a series of greenhouse-gas regulations on vehicles and power plants, Obama has promised to push forward on global warming, which stands tall as the largest failure in the administration’s legislative agenda coming into office.

Andrew Steer, president of the World Resources Institute in Washington DC, credited the Obama administration with investing in clean-energy technologies and implementing important greenhouse-gas regulations for cars and power plants. But like so many others working on this issue, he argues that this is not enough. “President Obama’s legacy will be shaped by his ability to take on big challenges, including climate change, clean energy, environmental protection, and sustainability” Steer said in a prepared statement.

Once the dust from the elections settles, lawmakers in the current Congress must return to Capitol Hill for a lame-duck session that will focus in large part on public debt. Unless Congress and the president can strike a deal on how to reduce a national debt that has now topped US$16 trillion, a 10% across-the-board spending cut will automatically take effect on 2 January. Irrespective of how that turns out, the political polarization will continue to challenge leaders in both parties once the next Congress convenes in January.

Obama nonetheless made it clear that he is ready to get to work. “Tonight, you voted for action, not politics as usual,” he told his supporters, once again promising to reach across the aisle in an effort to bring both parties together. If Obama's first term is any indication of what lies ahead, then fulfilling that promise will be his biggest challenge of all.