Likely Democratic caucus-goers think the former secretary of State is more electable.
Bush criticized Trump's claims about Sept. 11 and the treatment of a protester.
The video highlights Trump's remarks about Muslims and illegal immigrants.
Sanders and O'Malley took part, taking questions from the progressive group.
Complaints were also filed to keep Marco Rubio and Ted Cruz off the ballot.
Without strong action, "the entire NATO alliance comes into question,” Rubio said.
The Republican presidential candidate timed the surgery so he wouldn't miss any campaign events.
Trump is feuding with historians over Civil War history near one of his golf courses.
“Less than one term in the United States Senate has proven to be woeful training."
Julian Hattem 11/24/15 02:00 PM EST
Intelligence officials have been "demoralized," Christie said.