Louisville Democrat Charles Booker promised Wednesday to take his message about the shared interests of all Kentuckians to every corner of the state as he filed to challenge Republican U.S. Sen. Rand Paul in next year’s elections.

Booker submitted his paperwork a day after Democrats suffered a stinging loss in the governor’s race in neighboring Virginia. The defeat escalated alarms within the party about its broader prospects in next year’s midterm elections.

Booker, a former state lawmaker, already faces a daunting task in trying to unseat Paul, who is seeking a third term in a state trending solidly toward the GOP.

A Paul-vs.-Booker contest would present Bluegrass State voters with starkly different philosophies. Paul is a libertarian-leaning conservative who denounces deficit spending, foreign aid and government overreach. Booker promotes a progressive agenda with racial and economic justice themes.

Booker on Wednesday faulted Democrats for a willingness to “concede the narrative” to Republicans in rural parts of the nation. Looking to build an urban-rural coalition, the Black former lawmaker promised to take his “hood to the holler” themes to regions of Kentucky that have become GOP strongholds. The emphasis will be “on our common bonds,” Booker said.

“We have to show up and earnestly engage folks and listen to them,” he told reporters. “When I stood on the tracks with miners, they talked to me about sustainable energy. When I stood with teachers in western Kentucky, they told me how they want to fully and equitably fund public schools. When I speak to farmers, they’re understanding that climate change is real.”

Paul has tried to portray Booker as being out of step with the state’s electorate. The senator, who ran for president in 2016, has drawn attention to law enforcement and school governance issues seized on by other Republican candidates nationwide.

Paul’s deputy campaign manager, Jake Cox, said Wednesday that the senator “will continue his fight for fully funding our law enforcement and for parents rights.”

Booker rose to prominence as a U.S. Senate candidate in 2020 by touting racial and economic justice themes that coincided with protests erupting in Louisville and other cities across the country after the deaths of Breonna Taylor and other Black Americans in encounters with police. Booker touts Medicare for all, anti-poverty programs, a clean-energy agenda and criminal justice changes he says would help white Appalachians as well as people living in Louisville.

Paul was first elected to the Senate in the tea party-driven wave of 2010. He rails against socialism and big-government programs he says encroach on individual liberties and drive up the nation’s debt.

Booker narrowly lost last year’s Democratic Senate primary to Amy McGrath, an establishment-backed rival who was trounced by Senate Republican leader Mitch McConnell in the general election.

Kentucky has not elected a Democrat to the U.S. Senate since Wendell Ford in 1992.