WisconsinDemocrats see Republican Sen. Ron Johnson as a vulnerable incumbent.
Barnes has espoused progressive views in office, but his Senate campaign has focused more on pocketbook issues such as inflation and taxes.
Vance appears locked in a tight Senate race against Democratic Rep. Tim Ryan, despite running in a red-leaning state that Trump won handily in 2020.
Incumbent Democratic Sen. Maggie Hassan's approval ratings have fallen, including among unaffiliated voters who make up a major chunk of the state's electorate.
FloridaFormer Orlando police chief and Democratic Rep. Val Demings aims to unseat incumbent Republican Sen. Marco Rubio.