A national progressive group is spending over $100,000 on a campaign to pressure Senate Majority Leader Mitch McConnell and other Republican senators to pass a bill to provide $600 million in election security funding.

The group, Stand Up America, has rented a billboard alongside the Kennedy Bridge near McConnell’s office in downtown Louisville, Ky., from Sept. 1 through Sept. 9 that includes an image of McConnell’s face and the message, “Tell Mitch McConnell: Stop blocking election security funding.”

[Democrats target state elections with focus on election security]

In addition to McConnell, Stand Up America is targeting 10 other GOP senators — including six who will be defending vulnerable seats in the 2020 elections — with Facebook ads and by urging the group’s millions of activists to visit and call the senators’ offices to advocate for election security funding.

The House passed a bill earlier this year that would require $600 million in election security funding to be used to help states replace outdated electronic voting machines that are prone to hacking with machines that use voter-verified paper ballots.