Super Tuesday will be a defining moment in the race for the White House, as leading Democratic candidates battle for votes in 14 states — but they won't be the only names featured on the ballots.

Congressional races across the country stand to significantly reshape Capitol Hill depending on their outcomes, with numerous House incumbents facing difficult intra-party challenges during Tuesday’s primaries.

Voters in the following states will flock to the polls to partake in the biggest day of the primary calendar for congressional and Senate races: California, Texas, North Carolina, Virginia, Massachusetts, Minnesota, Colorado, Tennessee, Alabama, Oklahoma, Arkansas, Utah, Maine and Vermont.

Here are three key races to keep an eye out for on Super Tuesday:

Jeff Sessions fights to reclaim his Senate seat

The former US attorney general under Donald Trump has used his connections with the president to bolster his campaign for a Senate seat he held for nearly two decades.

But Mr Trump has not endorsed Mr Sessions in the Republican primaries, and the former attorney general’s opponents have used his recusal from former Special Counsel Robert Mueller’s investigation on Russian interference in the 2016 election as an example of his apparent disloyalty to the president.

Super Tuesday: Lively scenes as results flood in across 14 states Show all 29 1 /29 Super Tuesday: Lively scenes as results flood in across 14 states Super Tuesday: Lively scenes as results flood in across 14 states An anti-dairy protester is led away after storming the stage at Joe Biden's Super Tuesday event in Los Angeles, California EPA Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Bernie Sanders cheer as results are announced at a Super Tuesday party in Texas AFP/Getty Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Joe Biden hold up an election pooster from Barack Obama's 2008 run at a Super Tuesday event for the Democratic contender Reuters Super Tuesday: Lively scenes as results flood in across 14 states Bernie Sander takes to the stage before supporters during his Super Tuesday event in Vermont EPA Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Bernie Sanders cheer as results are announced at a Super Tuesday party in Texas AFP/Getty Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Bernie Sanders cheer as results are announced at a watch party in Texas AFP/Getty Super Tuesday: Lively scenes as results flood in across 14 states Joe Biden gestures to suppporters at a Super Tuesday event for the Democratic contender AP Super Tuesday: Lively scenes as results flood in across 14 states Elizabeth Warren waves to supporters at a rally in Michigan as results come in following Super Tuesday Getty Super Tuesday: Lively scenes as results flood in across 14 states A spray painted mural of presidential candidate Senator Bernie Sanders on the side of a building in Kirby, Vernont EPA Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Bernie Sandes cheer at a Super Tuesday rally in Vermont Getty Super Tuesday: Lively scenes as results flood in across 14 states Supporters of Elizabeth Warren hold sings and cheer in Cambridge Getty Super Tuesday: Lively scenes as results flood in across 14 states Democratic presidential candidate Elizabeth Warren leaves the voting booth at the Graham & Parks School in Cambridge, Massachusetts Getty Super Tuesday: Lively scenes as results flood in across 14 states A poster for sale at a rally for Bernie Sanders on Super Tuesday in Vermont Getty Super Tuesday: Lively scenes as results flood in across 14 states Democratic voter Elliot Zaagman wears a protective mask as he poses for a photo after casting his ballot in Bangkok, Thailand EPA Super Tuesday: Lively scenes as results flood in across 14 states Daisy, a Golden Retriever, outside a polling in San Diego. 1,357 Democratic delegates are at stake as voters cast their ballots in 14 states and American Samoa on what is known as Super Tuesday Getty Super Tuesday: Lively scenes as results flood in across 14 states Democratic presidential candidate Bernie Sanders (greets fellow voters after casting his ballot in his state's primary election at the Robert Miller Community Center in Burlington, Vermont Getty Super Tuesday: Lively scenes as results flood in across 14 states A first time voter stands behind a voting booth in a polling location for the North Carolina primary Reuters Super Tuesday: Lively scenes as results flood in across 14 states Democratic presidential candidate Michael Bloomberg takes part in his Super Tuesday night rally in West Palm Beach, Florida Reuters Super Tuesday: Lively scenes as results flood in across 14 states Fourteen states are holding their primaries with more than one third of the total pledged delegates in the Democratic primaries to be awarded on Super Tuesday Getty Images Super Tuesday: Lively scenes as results flood in across 14 states Presidential candidate Elizabeth Warren and her husband Bruce Mann greet supporters as they walk to a polling site to vote on Super Tuesday in Cambridge, Massachusett EPA Super Tuesday: Lively scenes as results flood in across 14 states Voters cast their ballots at a polling location inside an elementary school on Super Tuesday in Minneapolis, Minnesota EPA Super Tuesday: Lively scenes as results flood in across 14 states Democrat Jamie Wilson displays a sticker after voting in the Super Tuesday primary at John H. Reagan Elementary School in the Oak Cliff section of Dallas, Tuesday, March 3, 2020. (AP Photo/LM Otero) LM Otero AP Super Tuesday: Lively scenes as results flood in across 14 states Democratic voter Le'ana Freeman poses for a photo after casting her ballot at a polling station in Bangkok EPA Super Tuesday: Lively scenes as results flood in across 14 states Voters arrive to cast their ballots at a polling location inside Hunter House at Nottoway Park in Vienna EPA Super Tuesday: Lively scenes as results flood in across 14 states Democrat Jamie Wilson gets a sticker after voting in the Oak Cliff section of Dallas AP Super Tuesday: Lively scenes as results flood in across 14 states A Polling Place sign in the border town of Hidalgo, Texas EPA Super Tuesday: Lively scenes as results flood in across 14 states A girl carries her mothers ballot to the table where she will fill in her choice at the Taylor Elementary School polling location in Arlington Getty Images Super Tuesday: Lively scenes as results flood in across 14 states A man wearing an 'I Voted' sticker and a 'Bernie Abroad' badge after voting in the American presidential primary in Oxford, England Getty Images Super Tuesday: Lively scenes as results flood in across 14 states Stickers for people who vote AFP via Getty Images

Mr Sessions appeared to be leading in the polls against his two biggest competitors, Tommy Tuberville, a former football coach at Auburn University, and Bradley Byrne, an Alabama congressman.

If he secures the Republican nomination, Mr Sessions would then challenge Democratic incumbent Doug Jones — who won in a special election against Roy Moore, a controversial GOP candidate accused of sexual assault.

Will Pierce Bush keep his family’s political dynasty alive?

The grandson of former President George HW Bush (who is also a nephew to former President George W Bush) launched his candidacy for an open congressional seat in Texas’ 22nd district, among a crowded field of 15 candidates.

But the nonprofit leader is seen as a moderate in a race that features multiple vocal supporters of the president, Politico reported, potentially making his path to the nomination difficult on Tuesday.

If Mr Bush manages to win, analysts predicted he could fare well in a general election.

“Pierce Bush is in a very tight race,” Mark P. Jones, political scientist at Rice University, told Los Angeles Times. “The Republican Party realizes it’s in some trouble. Trump is a liability across the state of Texas, but he is especially a liability in Texas 22 because he has pushed a lot of Asian Americans, Indian Americans, away from voting Republican.”

Cal Cunningham takes on the president and his allies in North Carolina

The former state senator appeared set for a victory against his Democratic opponent in the state primaries, despite facing strong opposition from the president — who endorsed the Republican incumbent in the race and held a rally in Charlotte the night before the election — and his allies.

Mr Cunningham warned voters not to “get fooled” by a pricey advertising campaign opposing his candidacy ahead of Super Tuesday. That ad buying spree was reportedly funded by a Super PAC associated with allies of Mitch McConnell, the Senate Majority Leader.