Rep. Marsha Blackburn (R-Tenn.) during the South Carolina Freedom Summit hosted by Citizens United and Rep. Jeff Duncan (R-S.C.) in Greenville, S.C., on May 9, 2015. (Andrew Harrer/Bloomberg News)

Sen. Bob Corker (R-Tenn.), who has clashed with President Trump, is rethinking his political future and considering jumping back into this year’s Senate race, according to two Republicans close to him.

But the Senate campaign of Rep. Marsha Blackburn (R-Tenn.), now the front-runner for the GOP nomination, told The Washington Post on Tuesday that anyone who doubts her ability to win a general election against the likely Democratic nominee, former governor Phil Bredesen, is sexist.

And the Blackburn campaign tauntingly cast the sudden mulling by Corker, 65, as a vanity project.

“Anyone who thinks Marsha Blackburn can’t win a general election is just a plain sexist pig,” Blackburn campaign spokeswoman Andrea Bozek said in a phone interview. “She’s the best fundraiser in the country and is beating Phil Bredesen in several polls. We aren’t worried about these ego-driven, tired old men. Marsha has spent her whole life fighting people who told her she wasn’t good enough, and she will do it again.”

The two people close to Corker requested anonymity to speak candidly about their conversations with him. Politico reported Monday that Corker is “listening” to those encouraging him to run again.

Sen. Bob Corker (R-Tenn.) discussed his reasons for not seeking another term in office on Sept. 27. (Jordan Frasier,Jenny Starrs/The Washington Post)

Bozek’s sharp remarks underscore the tension within GOP ranks as a possibly bruising midterm election season gets underway. As some Republican consultants grow skittish about races that previously were not seen as vulnerable, others, such as Blackburn, are plowing ahead and increasingly frustrated with the party’s hand-wringing.

Tennessee’s Senate race, while in a reliably red state, is quickly becoming a marquee contest, especially as Democrats nationally see new possibilities in the South after the upset victory of Sen. Doug Jones (D-Ala.) in a December special election. Bredesen’s entry that same month gave Democrats a high-profile recruit with a proven record of winning statewide.

Blackburn, 65,  raised $2 million in the final quarter last year, and she had more than $4.5 million on hand last month. Her primary rival, former representative Stephen Fincher, raised about $1.5 million last quarter.

A senior adviser to Corker told a local newspaper Sunday that “it is true that Senator Corker has been encouraged by people across Tennessee and in the Senate to reconsider his decision, but at this point nothing has changed.”

The ultimate adjudicator in the tense Tennessee scramble could be the White House, which is eager to protect the GOP’s narrow Senate majority but has become wary of Corker since he began to publicly and harshly criticize the president last year. Vice President Pence’s political action committee has given money to Blackburn, who is known in Washington as a tea party favorite.