Former President Obama's ex-campaign manager Jim Messina said Wednesday that Sen. Bernie Sanders Bernie SandersOutrage erupts over Breonna Taylor grand jury ruling Dimon: Wealth tax 'almost impossible to do' Grand jury charges no officers in Breonna Taylor death MORE (I-Vt.) would not be able to beat President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE if the two were to face off in the 2020 general election.

Messina said during an episode of ABC News's Powerhouse Politics podcast that Trump would be able to defeat Sanders by highlighting the economy to sway swing voters.

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"I think if you look at swing voters in this country, they are incredibly focused on the economy," Messina said. "I think today you look at it and say that Bernie Sanders is unlikely going to be able to stand up to the constant barrage that is Donald Trump on economic issues."

Messina also said Sanders is well positioned to win the Democratic nomination.

"If nothing else, he will definitely be one of the final two or three candidates who has a shot at the nomination," Messina said.

He added that he considers Sen. Kamala Harris Kamala HarrisHarris faces pivotal moment with Supreme Court battle Nearly 40 Democratic senators call for climate change questions in debates Joe Biden has long forgotten North Carolina: Today's visit is too late MORE (D-Calif.), former Vice President Joe Biden Joe BidenBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Democratic groups using Bloomberg money to launch M in Spanish language ads in Florida Harris faces pivotal moment with Supreme Court battle MORE and former Rep. Beto O'Rourke Beto O'RourkeJimmy Carter says his son smoked pot with Willie Nelson on White House roof O'Rourke endorses Kennedy for Senate: 'A champion for the values we're most proud of' 2020 Democrats do convention Zoom call MORE (D-Texas) to be the other leading contenders.

"I think we need to let this process play out," Messina said. "We're going to find out if Bernie Sanders can can move a message to both swing voters and his base. We're going to find out if Joe Biden is battle tested. We're going to figure out whether Kamala Harris and Beto O’Rourke and [South Bend, Ind.,] Mayor Pete [Buttigieg] have the magic we think they have."

Along with Biden, Sanders has been at the top of the Democratic field in early 2020 polling. His campaign raised the most money among Democratic candidates in the first quarter of 2019.