Democratic pollster Mike Greenfield said in an interview that aired Thursday on "What America's Thinking" that the party is already in the process of rallying young voters ahead of the 2020 races.

"They definitely are," Greenfield, CEO and founder of Change Research, told Hill.TV's Jamal Simmons on Wednesday when asked if Democratic presidential hopefuls were focused on attracting young voters.

"That was one of the big successes of 2018 was rallying younger voters to come out and vote, and it's going to be really important for 2020," he continued.

Surveys show 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.) is currently leading the Democratic Primary pack with young voters, but other groups, such as white, working-class voters, have gotten a fair amount of attention, given their role in electing 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 in 2016.

Greenfield said that young voters would play a significant role in the primaries, as well as the general election.

"Our polling in the Democratic primaries shows that Bernie Sanders is still the most popular among younger voters, and it's not clear that any of the other candidates have gotten a huge amount of traction among that group," he said. "That's going to be a big thing both in the Democratic primary, as well as the general."

— Julia Manchester