He was a member of the South Carolina legislature in 1826 until 1832. He was extremely pro-slavery in his views. At the end of the Nullification Crisis in 1833, he told the South Carolina Nullification Convention: In 1832, Rhett became South Carolina attorney general and served until 1837. He was then elected US Representative and served until 1849. In 1838, he changed his last name from Smith to that of a prominent colonial ancestor, Colonel William Rhett. He objected vehemently to the protectionist Tariff of 1842.
Support for secession
On July 31, 1844, he launched the Bluffton Movement, which called for South Carolina to return to nullification or else declare secession. It was soon repudiated by more moderate South Carolina Democrats, including even Senator John C. Calhoun, who feared it would endanger the presidential candidacy of James K. Polk. Rhett opposed the Compromise of 1850 as against the interests of the slave-holding South. He joined fellow Fire-Eaters at the Nashville Convention of 1850, which failed to endorse his aim of secession for the whole South. After the Nashville Convention, Rhett, William Lowndes Yancey, and a few others met in Macon, Georgia on August 21, 1850, and formed the short-lived Southern National Party. In December 1850, he became U.S. Senator to complete the term left by the death of Calhoun. He continued to advocate secession in response to the Compromise, but in 1852, South Carolina refrained from declaring secession and merely passed an ordinance declaring a state's right to secede. Disappointed, he resigned his Senate seat. He continued to express his fiery secessionist sentiments through the Charleston Mercury, now edited by his son, Robert Jr. The 1860 Democratic National Convention met in Charleston, South Carolina and a large bloc of Southern delegates walked out when the platform was insufficiently pro-slavery. That led to the division of the party and separate Northern and Southern nominees for President, which practically guaranteed the election of an anti-slavery Republican, which in turn triggered declarations of secession in seven states. During the 1860 presidential campaign, a widely credited report in the Nashville Patriot said that the outcome was the intended result of a conspiracy by Rhett, Yancey, and William Porcher Miles hatched at the Southern Convention in Montgomery, Alabama, in May 1858.
Confederate States
After the election of the Republican Party's Abraham Lincoln, Rhett was elected to the South Carolina Secession Convention, which declared secession in December. He was chosen as deputy from South Carolina to the Provisional Confederate States Congress in Montgomery. He was one of the most active deputies and was the chairman of the committee that reported the Confederate States Constitution. He was then elected to the Confederate House of Representatives. He received no higher office in the Confederate government and returned to South Carolina. During the rest of the American Civil War, he sharply criticized the policies of President Jefferson Davis.
Later life
After the war, Rhett settled in Louisiana. Contrary to rumors, he was not a delegate to the 1868 Democratic National Convention. It was his son, Robert Rhett Jr., who had shared his father's editorship responsibilities. He died in St. James Parish, Louisiana, and is interred at Magnolia Cemetery in Charleston.
