Biden’s strong showing among African Americans, suburbanites and moderate white voters — spanning geographical regions and drawing from a surge in turnout — boosted confidence among Democrats that the former vice president could soon win a Democratic race that voters have turned into a contest over which candidate is best positioned to beat Trump…

The results also harked back to the 2018 midterm elections, in which Democrats won back the House and prevailed in several competitive gubernatorial races by capitalizing on disdain for Trump among moderate and suburban voters, combined with high turnout among members of the Democratic base.

Rep. Joe Cunningham (D-S.C.), who flipped a Republican congressional seat in 2018, said Biden’s string of victories was reminiscent of his win in a district containing the suburbs of Charleston.

“A lot of folks who came out and supported us are the same ones who came out and supported him,” said Cunningham, who endorsed Biden.