The arrival last year of Mr. Carter and 14 other newly elected Democrats made it possible for Democrats to expand Medicaid. Now the party is aiming to take control of the state legislature this coming November, a goal that once seemed out of reach.

The upcoming election also sets the stage for a struggle over Virginia’s future between those who believe that prosperity lies in wooing more businesses and those like Mr. Carter, who believe it comes from making businesses share more of their wealth. While Virginia is the 12th largest economy in the country by gross domestic product, according to the Virginia Economic Development Partnership, it ranks 26th in income equality, according to the American Community Survey.

Mr. Carter has been a vocal opponent of the incentive package, worth more than half a billion dollars, used to lure one of Amazon’s new headquarters to Crystal City, Va. And he fought against a bill overhauling the state’s energy grid, arguing that it gave away too much to Dominion, a powerful for-profit utility.

In recent days, Mr. Carter filed a bill that would get rid of the union-weakening “right to work” statute that has been in place since 1947, as well as another bill that would give public employees, including teachers, the right to strike.

He is the first to admit that these bills have little chance of passing this session, since Republicans hold a slim majority in both chambers of the state legislature, and even some Democrats oppose them.

“One of the biggest things has been trying to keep in mind that by electing a socialist, my constituents have made the choice to reject the status quo,” he said. “They want someone to go and fight, even if that person is on the losing end.”

But it is not clear how many of Mr. Carter’s constituents know that he is a socialist. More than a dozen voters on the streets of Manassas expressed surprise to learn that the district is represented by a lawmaker who embraces that label.