A Republican and a former high school teacher, he served in the Virginia House of Delegates from 1990 to 2022, representing the 66th District.

In October 2020, Cox filed papers to establish a campaign committee preparing to seek the Republican nomination for Governor of Virginia, but said he would not formally announce until after the November presidential election.

OVN is an online consortium that offers degrees in high demand fields from Virginia public universities.

WTKR reported that "no other prevalent health condition—including asthma, diabetes and cancer—has coverage limits that are imposed based on the patient's age.

Cox has opposed the court's ruling, conceding that the map had been drawn to gain political advantage, but not to suppress voters based on race.

[16] In July 2019, Cox formally closed a special session on gun control after 1 hour and 30 minutes of deliberation between fellow delegates.

[17][18] In the 2019 election, Cox was re-elected to a 16th term, but the Republicans lost their majority, making it the first time since 1997 Democrats won the House of Delegates.