Dixon was elected to represent Henderson County in the
Kentucky House of Representatives in 1830. He served three consecutive one-year terms, leaving the House in 1833. From 1836 to 1840, he represented Henderson,
Daviess, and
Hopkins counties in the
Kentucky Senate. Among them were assertions that slave property was just as inviolable as any other property, that the rights of property were above constitutional sanction, and that absolute power over property cannot exist in a republic. Clay drew about 6,000 votes, mostly from Whigs, and Powell won the election by a small majority. The Assembly acted according to Clay's plans. By a vote of 71–58, they chose Dixon over Democrat James Guthrie to assume Clay's seat effective September 1. However, Clay died on June 29, 1852. Because Dixon's commission stipulated an effective date of September 1, Governor Powell proceeded to name Clay's successor for the period until September 1. He chose Democrat
David Meriwether, who served those two months, then, with respect to the original commission issued by the legislature (or by simply not returning to the Senate upon the commencement of the next session), effectively relinquished the seat to Dixon. Douglas hoped to placate southerners with this language, which allowed for the possibility of legalized slavery in the potential state without specifically addressing the issue of the Missouri Compromise. Southerners, however, saw that Douglas' attempt was unlikely to result in legalization of slavery. While it allowed Nebraska to determine whether slavery would be legal there when it became a state, slavery was still forbidden under the Missouri Compromise as long as it remained a territory. If no slaveholders were allowed in the territory, it would be exceedingly unlikely that the state's voters would allow for slavery in their constitution. Following this line of thought, Dixon drafted an amendment to Douglas' bill that would repeal section eight of the Missouri Compromise, the section that prohibited slavery north of latitude 36°30'. After a promise of support from
Tennessee senator
James C. Jones, Dixon introduced the amendment on January 16, 1854. This forced Douglas to confront the Missouri Compromise issue outright, and two days later, he visited Dixon to discuss his position. Douglas was reluctant to repeal the Compromise, but was ultimately convinced by Dixon's logic. He concluded the interview by exclaiming "By God, Sir, you are right. I will incorporate it in my bill, though I know it will raise a hell of a storm." Over the next several days, Douglas incorporated Dixon's suggestion and other pro-slavery measures into the Kansas-Nebraska Act, which President
Franklin Pierce signed into law on May 30, 1854. ==Later life==