A senior campaign adviser for the Sanders campaign said Wednesday that Vice President Joe Biden Joe BidenThe Memo: Warning signs flash for Trump on debates Senate Republicans signal openness to working with Biden National postal mail handlers union endorses Biden MORE's performance on Super Tuesday was due to the Democratic establishment rallying behind him.

"The establishment consolidated around one person," Chuck Rocha told Hill.TV. He said Biden got momentum from former South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBogeymen of the far left deserve a place in any Biden administration Overnight Defense: Woodward book causes new firestorm | Book says Trump lashed out at generals, told Woodward about secret weapons system | US withdrawing thousands of troops from Iraq A socially and environmentally just way to fight climate change MORE and Sen. Amy Klobuchar Amy KlobucharEPA delivers win for ethanol industry angered by waivers to refiners It's time for newspapers to stop endorsing presidential candidates Biden marks anniversary of the Violence Against Women Act, knocks Trump and McConnell MORE (D-Minn.) dropping their White House bids shortly before Super Tuesday.

"Those voters who were with Pete, those voters who were with Amy...there's no way to gauge that kind of consolidation within 48 hours of an election," Rocha added.

Buttigieg and Klobuchar both endorsed Biden before the polls opened on Tuesday, giving him a much-needed boost with moderate voters.

Coming off a decisive victory in Saturday's South Carolina primary, Biden carried that momentum into Super Tuesday, winning the majority of the 14 state contests and notching a few upsets in states like Massachusetts and Minnesota.

Biden was leading Sanders in the delegate count as of 2:20 p.m. ET on Wednesday.

Rocha said that with Super Tuesday data in hand, the Sanders campaign will be able to respond accordingly.

Idaho, Michigan, Mississippi, Missouri, North Dakota and Washington state all have their primaries on Tuesday.