Bredesen is 74, and was the mayor of Metro Nashville from 1991 to 1999.
Blackburn, 65, has served in the U.S. House of Representatives since 2003.
Mackler, 45, is an Army Reservist and Iraq War veteran.
All are seeking the seat being vacated by Sen. Bob Corker, a businessman and former Chattanooga mayor who has announced that he will not run again.
Bredesen touted his record as mayor of Nashville, and as governor:
“When I was sworn in as governor, TennCare was out of control and our bond rating was headed south. And then we had the meltdown of the Great Recession. With a lot of hard choices, we managed our way through all of that — without an income tax and without raising the sales tax. And we didn’t just get through it, we prospered. We put new money in education — especially in teacher’s salaries. We brought in new jobs and investment. Our rainy-day fund hit new highs and we achieved a triple A bond rating — the best there is.”
On Wednesday night, Blackburn spokeswoman Andrea Bozek released this statement:
“Tennessee families want change and that is not what 74-year-old Democrat politician Phil Bredesen will bring to the United States Senate. Bredesen’s views are out-of-touch with Tennessee values, he supported President Obama’s liberal policies, is against second amendment rights and even authored a plan to give illegal immigrants driving certificates. Marsha is the only true conservative in this race who will ensure liberal Bredesen doesn’t block President Trump’s agenda in Washington.”