The biggest day on the Democratic presidential calendar could establish a front-runner, lock in a two-person race and settle the fate of wild cards.
Bernie Sanders is up in California, home of the biggest trove of delegates, although Joe Biden's big South Carolina win appears to be registering in recent surveys.
In her sharpest attack yet on the former vice president, Warren says Biden is a risk to the Democratic Party and the country.
"They're going to put him into a home, and other people are going to be running the country," the president said of the former vice president at a campaign rally in Charlotte Monday.
Pressure increases on Mike Bloomberg as candidates exit the race and back Joe Biden.
Analysis: At the last possible moment, former rivals are coalescing behind the former vice president to try to blunt Bernie Sanders' edge heading into Super Tuesday.
The former South Bend mayor's backing came less than a day after he ended his own presidential bid.
The Senate must confirm as DNI a Texas congressman who inflated his resume, or leave in place an acting director without significant intel experience.
Amy Klobuchar is dropping out of the presidential race, a campaign official confirmed on Monday.
Bump stocks allow a shooter to fire continuously with a single pull of the trigger and figured prominently in the Las Vegas mass shooting in 2017.
The Vermont senator had said the pro-Israel lobbying group provides a platform "for leaders who express bigotry and oppose basic Palestinian rights."
The Supreme Court said Monday that it will take up a legal challenge to Obamacare, agreeing to hear the case in its new term that begins in October. That means the program will continue for at least another year.
First Read is your briefing from "Meet the Press" and the NBC Political Unit on the day's most important political stories and why they matter.
More delegates will be allocated on Super Tuesday than any other day on the presidential primary calendar.
The announcement comes after a poor showing in South Carolina's Democratic primary.
"Look, you don't change the rules in the middle of a game," Biden said.
Half the states will vote this month, forcing candidates to raise massive amounts of money and compete in dozens of places at once.
Meanwhile, top Democrats criticized the president over his handling of the outbreak.
The Massachusetts Senator is still trying to find ways to challenge a front-runner she shares common policy ground with.
"The real politicians ate them up and spit them out!" he said of billionaires Bloomberg and Tom Steyer.
The two states award a combined 338 delegates on Super Tuesday.
Data Download has a look at primary votes within the Super Tuesday vote.
Analysis: The former vice president resurrected his campaign with a convincing victory, but he may have to do better to catch up with Bernie Sanders.
The announcement came after an underwhelming finish in the South Carolina Democratic primary.
Bernie Sanders has pulled into the lead nationally, but the former VP is hoping his strength with black voters could give him a boost.
The president announced the briefing following reports of additional cases in the United States.