After a period in private practice, he was elected District Attorney in northeast Johnson County, serving in that capacity from 1977 to 1989.

The district had traditionally elected moderate Republicans, but Snowbarger's unyielding conservatism caused many voters to shift to Moore.

His margin of victory was fairly close believed to be due to George W. Bush's strong performance in the district.

In the 2006 Congressional election, Moore successfully defended his seat against Republican Chuck Ahner, winning with 64% of the vote, a much larger margin than he had in the past.

In August 2007, Republican State Senator Nick Jordan of Shawnee announced he would challenge Moore for the 3rd District seat in 2008.

[8]Representative Moore sponsored HR 5055,[9] which would have raised the death gratuity paid to the family of a soldier who died in combat from $12,000 to $50,000.

[12] Representative Moore sponsored House Resolution 387[13] in 2003, calling on the Department of Defense to cover all travel costs for troops from Iraq and Afghanistan granted leave under the Rest & Recuperation Program.

[10] For 2007, with points assigned for actions in support of or in opposition to American Land Rights Association position, Representative Moore received a rating of 8 (out of 100).

[15] In 2008, the NRA Political Victory Fund gave Representative Moore a grade of F, in its scorecard for candidates seeking office in 2008.

[19] For 2007–2008, with points assigned for actions in support of or in opposition to National Right to Life Committee position, Representative Moore received a rating of 0.

[20] The environmental watchdog group League of Conservation Voters gave Moore a score of 92% for 2006, citing pro-environment votes on eleven out of twelve issues deemed critical by the organization.

[24] On November 2, 2021, Moore died from cancer, aged 75, at a care facility in Overland Park, Kansas, where he had lived for the previous three years.