"It was a long-shot, but we wanted to try and interject this issue, how much we're spending, into the national debate which comes along once every four years," Sanford said, according to The Associated Press. "I don't think on the Republican side there is any appetite for a nuanced conversation on issues when there's an impeachment overhead."
Sanford was one of three Republicans to challenge Trump for the presidential nomination.
In February, former Massachusetts Gov. William "Bill" Weld announced a bid for the GOP presidential nomination. Former U.S. Rep. Joe Walsh, R-Ill., announced in August that he planned to run for the Republican presidential nomination.
The Associated Press contributed to this report.