Lt. Gov. Mandela Barnes begins fundraising for a potential U.S. Senate run

The countdown has begun to a potential U.S. Senate run by Mandela Barnes.

Wisconsin's lieutenant governor has begun fundraising efforts for a possible campaign, according to a tweet posted Thursday by Ana Garcia-Ashley, who runs a Milwaukee non-profit.

Under federal campaign rules, potential candidates have a 15-day period in which they can raise money to test the waters before they have to file paperwork to officially enter the race.

"Join me in supporting Mandela Barnes via ActBlue," the since-deleted tweet said.

The link to a fundraising website said: "Let's be bold and unafraid to work together to change the game by sending Mandela Barnes to the US Senate! Become a founding donor to our campaign by making a donation today."

A spokesperson for Barnes declined to comment.

If Barnes gets into the race he'll become one of the three Democratic front runners for the seat currently held by Republican U.S. Sen. Ron Johnson. The other top-tier candidates feature state Treasurer Sarah Godlewski and Alex Lasry, on leave from his executive job with the Milwaukee Bucks.

More:Meet the 5 Democrats already running for Ron Johnson's seat in Wisconsin's 2022 Senate race

Johnson has not announced if he'll run for a third term.