WASHINGTON - Republicans took first blood Tuesday in the midterm battle to seize the US Senate, winning a key Democratic seat and heaping pressure on President Barack Obama's party to hold its ground.
With most polls closed in the eastern third of the nation, confident Republicans enjoyed a huge sigh of relief when Senate Minority Leader Mitch McConnell, the man who could lead the chamber should the GOP win the majority, brushed aside Democrat Alison Lundergan Grimes, his toughest challenger in more than 30 years.
Republicans also romped to victory in West Virginia - where retiring Democrat John Rockefeller had held the seat for decades - marking the first of six pickups that the party would need in order to take control of the 100-member Senate.
The first results confirmed that Obama's adversaries were on course to win a majority in both chambers of Congress for the first time since 2006 and blight the president's last two years in office.
Democrats - working feverishly to draw voters to the polls in a last-gasp effort to stave off disaster - could lose Senate seats in as many as 10 of the 36 states in play.
With no legislative base in Congress, Obama will struggle to pass any reforms in the final stretch of his mandate, and his opponents will be able to thwart his appointments to judicial and official posts.
The party of an incumbent president historically fares badly in elections in his second term, and every president since Ronald Reagan has left office with the opposition controlling Congress.
The Republicans essentially based their campaigns on attacks against Obama and policies like his troubled health care reform.
Although the economy has improved gradually since the 2008 recession, the national mood is far from buoyant - a sentiment reflected in Tuesday exit polling.
Two-thirds of respondents said the country was on the wrong track, according to an ABC exit poll.
Meanwhile, a CNN exit poll showed 79 per cent disapproved of Congress and less than one-third were satisfied with the Obama administration or with Republican leaders.
Recent economic gains have not translated into support in swing states with Democratic senators - such as Alaska, Arkansas, Colorado and Louisiana - which Republicans could now win.
'Worst' map for Democrats
Acutely aware of how his low approval rating makes him a lightning rod, Obama acknowledged that this election cycle's Senate map has made it the toughest uphill battle for his party in half a century.
"This is probably the worst possible group of states for Democrats since Dwight Eisenhower," Obama told WNPR, a radio station in safely Democratic Connecticut.
Democrats hold a 55 to 45 seat advantage in the Senate. Republicans already control the House of Representatives and are expected to retain it.
McConnell said recently that Republicans would be "responsible" Senate leaders, even potentially cooperating with Obama on issues like tax reform.
But the party will seek to breathe life into their many stalled jobs bills, gain approval of the delayed Keystone XL pipeline, roll back some carbon emission regulations and tweak Obamacare.
Voters will also elect dozens of state governors and hundreds of local legislators, while voting in referendums on dozens of state-level issues, including in some places the legalizing of marijuana.
A muddled picture?
However successful the Republicans are, a complete picture may not emerge Tuesday.
There are strong prospects for runoffs in Democrat-held Louisiana and Republican-held Georgia, where rules require a second round if winners do not earn more than 50 per cent of the vote.
Add to that a probable days-long ballot count in remote Alaska, where there is an unpredictable and tight race.
Louisiana's runoff would be on December 6, but a Georgia runoff would be on Jan 6, which means senators may not know who controls the chamber when Congress opens January 3.
At 8:00 pm (0900 GMT+8 Wednesday), Georgia and the crucial Democratic state of North Carolina remained too close to call.