Biden said he would contest nomination even if Sanders leads in delegates: 'You don't change the rules in middle of the game'

Former Vice President Joe BidenJoe BidenMinnesota certifies Biden victory Trump tells allies he plans to pardon Michael Flynn: report Biden says staff has spoken with Fauci: 'He's been very, very helpful' MORE said Sunday he would contest the presidential primary nomination at the Democratic  convention if Sen. Bernie SandersBernie SandersBiden: 'Difficult decision' to staff administration with House, Senate members Hillicon Valley: YouTube suspends OANN amid lawmaker pressure | Dems probe Facebook, Twitter over Georgia runoff | FCC reaffirms ZTE's national security risk Biden Cabinet picks largely unify Democrats — so far MORE (I-Vt.) is leading in delegates without securing a majority. 

“The rules have been set,” Biden said on CNN’s “State of the Union.” 

Biden questioned Sanders’ take that the candidate with a plurality of pledged delegates the convention should become the nominee. 

“I wonder where that view was when he was challenging Hillary when she went in with a commanding lead,” Biden added. “You don't change the rules in the middle of the game.” 

Sanders is the only candidate in the field this year to insist that the candidate with the most pledged delegates should be the party nominee. He held the opposing view in 2016 when facing former Secretary of State Hillary ClintonHillary Diane Rodham ClintonIntercept DC bureau chief says Biden picks are 'same people' from Obama years The Hill's 12:30 Report - Third vaccine candidate with 90% efficacy Biden won — so why did Trump's popularity hit its highest point ever? MORE

Biden’s commitment to challenge the nomination comes after he won his first primary in South Carolina on Saturday. 

Biden is trailing Sanders in the number of pledged delegates as the candidates head into Super Tuesday, when the largest number of states will hold primaries and caucuses including Texas and California.