Casada denies offering National Guard promotion, pork barrel projects to win votes on Tennessee Gov. Bill Lee's school voucher bill

State Rep. and Speaker of the Tennessee House Glen Casada speaks during the Hamilton County Republican Party's annual Lincoln Day Dinner at the Westin Hotel on Friday, April 26, 2019 in Chattanooga, Tenn.

NASHVILLE - Tennessee House Democrats are demanding an investigation into allegations departing Republican Speaker Glen Casada offered to get a reluctant Democrat a top National Guard promotion in an effort to muscle Gov. Bill Lee's controversial school voucher bill through the chamber in April.

Casada, who is resigning Aug. 2 under pressure from an unrelated scandal, denied the allegation in a Facebook posting Sunday.

Over the weekend, WTVF reported that Rep. John Mark Windle, a Livingtson Democrat, said he rejected an effort by Casada to "buy" his vote on Lee's education savings account bill as they stood on an outdoor balcony adjoining the House chamber.

The Nashville television station reported that another lawmaker overheard Casada suggesting to Windle, a National Guard colonel, he could be promoted to general in exchange for his vote.