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 Biden2020 Democratic Party platform endorses Trump's NASA moon program Don't let Trump distract us from the real threat of his presidency Abrams: Trump 'doing his best to undermine our confidence' in voting system MORE said Sunday he would contest the presidential primary nomination at the Democratic  convention if Sen. Bernie SandersBernie SandersGOP lawmaker: Democratic Party 'used to be more moderate' 4 reasons why Trump can't be written off — yet Progressives lost the battle for the Democratic Party's soul 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 ClintonState polling problematic — again 4 reasons why Trump can't be written off — yet 'Unmasking' Steele dossier source: Was confidentiality ever part of the deal? 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.