DAY IN A NUTSHELL
The Republican candidates take part in a televised debate in South Carolina, Hillary Clinton heads to Nevada, and Barack Obama goes to South Carolina where he receives an endorsement from 2004 Democratic presidential candidate John Kerry. Bill Richardson drops out of the Democratic race, prompting speculation as to whether his strong following among Hispanic-Americans will now transfer to one of the Democratic frontrunners.
"Maybe I have liberated us to actually let women be human beings in public."
Hillary Clinton, talking about the moment in New Hampshire when she appeared tearful
"If journalists were candidates, there would be insurmountable pressure for us to leave the race."
John F. Harris and Jim VandeHei, Politico.com
"Mrs Clinton won the beer drinkers, Mr Obama the white wine crowd. And there are more beer drinkers than wine swillers in the Democratic Party."
Karl Rove, Wall Street Journal
"The media loves process. Talking heads love chatter. But Florida has a chance to turn down the noise and show the world that leadership is what really matters."
Campaign advert for Rudy Giuliani
John McCain will be pleased with a Strategic Vision poll which suggests that he has a nine-point lead in Michigan, with 29% to second-placed Mitt Romney's 20%, and Mike Huckabee's 18%.
But another poll of Michigan voters (from Rossman Group/MIRS/Denno-Noor) suggests that Mr Huckabee is in the lead with 23%, ahead of Mr Romney on 22% and Mr McCain on 18%.
The situation in South Carolina is also rather confused: an Insider Advantage poll indicates that Mr Huckabee is in the lead with 33% to Mr McCain's 21%, but a Rasmussen poll suggests that Mr McCain leads in the state, with 27% to Mr Huckabee's 24%.
Both Insider Advantage and Rasmussen give strong leads to Barack Obama in the South Carolina Democratic race.
Will John Kerry's endorsement of Barack Obama improve the Illinois senator's chances in the Democratic race?