Washington (CNN) Republican Sen. Josh Hawley told reporters on Wednesday afternoon that he spoke with Supreme Court Justice Clarence Thomas about controversial Trump judicial nominee Neomi Rao.

Hawley has created an uproar in the conservative judicial community in the last few days over his concerns with Rao, who is President Donald Trump's pick to replace Brett Kavanaugh on the DC Circuit Court of Appeals, a court that's often a stepping stone to the Supreme Court.

A source familiar with Hawley's thinking told CNN that he is mainly concerned with Rao's judicial philosophy and the lack of a record on substantive due process. She's never been a litigator on the subject, so he cannot tell how she would act, but her writings indicate she might be OK with substantive due process, according to the source.

On Wednesday before his meeting with Rao, Hawley expressed that he looked forward to talking with her about "her judicial philosophy, discussion about her legal views on substantive due process in particular."

Hawley said he thinks it's important that senators "ask tough questions. I was sent here to ask tough questions, to vet these nominees, and to do my job and that's what I'm doing."

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