DAY IN A NUTSHELL
Barack Obama sweeps to victory in the three Democratic primaries in Virginia, Maryland and Washington DC.
For the Republicans, presumptive nominee John McCain also wins all three contests, although his rival Mike Huckabee mounts a strong challenge in Virginia, taking more than 40% of the vote. Hillary Clinton unveils a stellar endorsement from former astronaut and Ohio Senator John Glenn.
"My friends, I promise you, I am fired up and ready to go."
John McCain ends his victory speech with one of Barack Obama's signature lines
"With all of the challenges facing Ohio and America, we need a leader who can deliver real solutions on her first day in office."
Former senator and astronaut John Glenn endorses Hillary Clinton
"The nomination is not secured until one candidate has 1,191 delegates."
"John McCain is an American hero. We honour his service to our nation... But his priorities don't address the real problems of the American people, because they are bound to the failed policies of the past."
Barack Obama turns his sights on the Republicans in his victory address
"In the dark days when Iraq's al-Anbar province was the bloodiest place on the planet - John McCain was one of the few in Congress brave enough to venture into that cauldron. I know, because I saw him there."
Col Oliver North
Because many pollsters assumed that the presidential races would be settled after Super Tuesday, little polling has been done in the states holding contests later on in the primary calendar.
So polls published today from Wisconsin and Ohio shed some much-needed light on the state of the races in those states.
A Public Policy Polling survey of Wisconsin voters suggests that Barack Obama and John McCain have the advantage there. The poll has Mr Obama leading Hillary Clinton by 50% to 39% and Mr McCain leading Mr Huckabee 53% to 32%.
Mr McCain also leads Mr Huckabee in the SurveyUSA poll of Ohio voters (50% to 36%), but for the Democrats in Ohio, Mrs Clinton has the lead - with 56% to Mr Obama's 39%.
Turnout in Virginia, Maryland and Washington DC was much higher than in previous years, in spite of poor weather