NASHVILLE (AP) — Tennessee state Rep. Gloria Johnson, the lone Democratic member of the "Tennessee Three" who narrowly survived a Republican-led expulsion effort, has launched an exploratory committee as she considers running for the seat held by U.S. Sen. Marsha Blackburn in 2024.

Johnson, 61, filed the exploratory paperwork — a step that usually comes just before officially launching a campaign — late last week. Doing so allows her to start raising money to support efforts like traveling and polling without officially becoming a candidate. It's not required to run for political office but it can help boost a candidate's profile.

"Tennessee has a Senator that stands with bullies, I have a reputation for standing up to bullies," Johnson said in a statement. "I'm taking a serious look at this race and having great conversations with folks who are hungry for better leadership in Washington."

In ruby red Tennessee, Johnson is expected to face an uphill battle if she advances to face Blackburn. The state hasn't elected a Democrat to a statewide office since 2006.

Johnson has long been a vocal critic of Blackburn and other top Tennessee Republican leaders during her time in office. However, it wasn't until this spring that her political career received a national boost after she participated in a pro-gun control protest inside the Tennessee Capitol that attracted thousands of protesters demanding lawmakers address the state's lax gun laws.

The demonstration came just days after a shooter opened fire at a private Christian school in Nashville, killing three children and three adults. With tensions running high, Johnson joined fellow Democratic Reps. Justin Pearson and Justin Jones as they approached the front of the House floor without permission with a bullhorn, joining the chants and cries for action by protesters in the public galleries and outside of the chamber.

Republican lawmakers quickly called for their expulsion because they broke protocol and disrupted House proceedings. Pearson and Jones, who are both Black, were expelled, while Johnson, who is white, was spared by one vote, though Republicans denied that race was a factor. Pearson and Johnson were reinstated on an interim basis and were reelected to their positions last week.

All three will join their legislative colleagues later this month for a special session to address possible changes to the state's gun control laws. Republican lawmakers initially declined to do so before adjourning their regular session in April. Republican Gov. Bill Lee, who has pushed for changes to keep guns away from people deemed to pose a threat to harm themselves or others, is calling them back into session.

Blackburn's first Senate race took place in 2018, when she defeated Democratic former Gov. Phil Bredesen by almost 11 percentage points.

Blackburn's win, where she also became Tennessee's first female U.S. senator, marked a stark rightward shift in the state's Republican Party leaders. While former GOP senators from the Volunteer State were known for taking more centrist positions, Blackburn launched her senate campaign by touting that she was a "hardcore, card-carrying Tennessee conservative" and aligned herself closely to former President Donald Trump.

In 2021, she vowed to oppose the electoral college results that affirmed President Joe Biden's win, but later backed down after watching the Jan. 6 insurrection unfold from inside the U.S. Capitol.

Along with Johnson, Democratic community activist and organizer Marquita Bradshaw has also announced plans to run for Blackburn's seat. Bradshaw won the Democratic Senate nomination in 2020, but later lost to Republican U.S. Sen. Bill Hagerty in the general election by 27 percentage points.

"At the urging of Washington liberals, Gloria Johnson has taken another critical step towards joining liberal Democrat Marquita Bradshaw in the Tennessee Senate Democratic Primary," said Blackburn's campaign spokesperson, Abigail Sigler. "Both of them are radical socialists who are aligned with Joe Biden's failed policies that are making Tennesseans' lives tougher every day."