[2][3][4] In his first term as State Representative, David audited the Department of Revenue and found $36 million in potential savings for Missouri taxpayers.

[5] To implement his findings, the then Director of the Department of Revenue, Ken Zellers created an ongoing initiative called, Strike Force Gregory.

[3] He was named Freshman Legislator of the Year for outstanding work on preventing government waste, fraud and abuse.

[7] In 2021, he announced his intentions to investigate ways to counter anti-competitive practices in the meat-packing industry that negatively impact Missouri cattlemen.

[8] Gregory was elected to the Missouri Senate in 2024, representing the 15th District which covers west St. Louis County.

In December 2024 Gregory pre-filed a bill that would create the Missouri state felony of trespassing for any illegal alien who knowingly enters and remains in the state, punishable by imprisonment for life,[9] and authorizing bounty hunters to enforce federal immigration policy.

[12] House Republicans did not present a corresponding bill and Speaker Jon Patterson expressed a "lack of enthusiasm" for a bounty proposal, saying that the issue is being addressed at the federal level.