(CNN) Tennessee GOP state House Speaker Glen Casada faced calls on Tuesday to step down after his chief of staff resigned following reports that the top aide had made racist comments, sent sexually explicit messages to interns and allegedly tried to frame an activist.

Cade Cothren, Casada's former chief of staff, resigned Monday, Tennessee House GOP spokesman Doug Kufner confirmed to CNN. On Tuesday, top Democrats in the state called for the speaker to step down as well.

on Tuesday, Casada continued to vouch for Cothren's character as he confirmed the chief of staff had resigned. Casada stood by Cothren throughout many of the revelations, initially disputing reports that he and Cothren later acknowledged were partly true and vouching for his aide's character even as pressure mounted. In a radio interview on Tuesday, Casada continued to vouch for Cothren's character as he confirmed the chief of staff hadresigned

"Why he's resigning is things that he did before he turned his life around," Casada told WWTN-FM on Tuesday. The speaker also pitched the House's "bold, conservative leadership" and called his own participation in sexual and derogatory messages with Cothren "locker room talk."

In a statement on Tuesday, Casada announced a new chief of staff, Scott Gilmer, would replace Cothren.

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