He ran against Sam Houston and Stephen Austin in the 1836 presidential election, but was soundly defeated by Houston, though he did edge out Austin. Smith was appointed by Houston to serve as his Secretary of the Treasury during his first administration. Later he promoted development along the Texas Gulf Coast. In 1840 he was elected to the Fifth Congress of the Republic of Texas, serving in the House of Representatives, though he retired after just one term. He never sought another public office.