 Comstock supported Trump's proposed border wall on the Southern border.In February 2018, Comstock “generated national headlines when she rebuked the president during a meeting...at the White House on the dangers of the deadly gang MS-13.” Trump said that “if congressional Democrats would not support a legislative crackdown on dangerous illegal immigrants, he would advocate shutting down the federal government.“ Comstock replied, “We don't need a government shutdown...I think both sides have learned that a government shutdown was bad, it wasn't good for them.” While Comstock described the exchange as "a polite conversation,” "The Washington Post" said that “[e]veryone else called it an extraordinary public scolding of a sitting U.S. president.”

In 2018, the U.S. Senate passed a bill introduced by Comstock which gave the federal government greater latitude in deporting immigrants who were suspected of gang activity.Comstock opposed same-sex marriage.