WASHINGTON (WIAT) — U.S. Sen. Richard Shelby (R-Alabama) will not be backing Judge Ketanji Brown Jackson’s nomination to the Supreme Court.

On Thursday, Shelby met with President Joe Biden’s pick to replace Justice Stephen Breyer to discuss a slew of topics, including Jackson’s qualifications and credentials.

“We had a candid discussion in which I questioned her about my concerns, such as her judicial philosophy, position on court-packing, and prior sentencing record as a judge,” Shelby said in a statement. “While I enjoyed meeting Judge Jackson, her answers did not sufficiently alleviate my concerns. As such, I am unable to support her nomination to the Supreme Court.”

Sen. Tommy Tuberville met with Jackson on Tuesday and said he would “continue to carefully review her record and judicial philosophy, and will listen to the people of Alabama in making my final decision on her nomination.”

Earlier this week, Maine Sen. Susan Collins became the first Republican to endorse Jackson’s nomination. Her endorsement came after a meeting where Collins said: “she possesses the experience, qualifications, and integrity to serve as an Associate Justice on the Supreme Court.”

If selected, Jackson would become the first Black woman to serve on the Supreme Court. A final vote by the Senate is set to be made on her nomination by April 8.