By Sam Gringlas Sen. Katie Britt, R-Ala., arrives for a meeting on Capitol Hill on June 18, 2024. Britt has taken on a leading role helping negotiate changes to immigration enforcement. Andrew Harnik/Getty Images hide caption Stay up to date with our Politics newsletter, sent weekly. Two years ago, Republican Sen. Katie Britt of Alabama accepted what is often called the worst assignment in politics — rebutting the president's State of the Union address. The televised response, broadcast live from Britt's tidy kitchen in Montgomery, was the Alabama freshman's introduction to a national audience, and what many viewers saw was an over-the-top firebrand, parodied as a "scary mom" by actress Scarlett Johansson on Saturday Night Live. "The American dream has turned into a nightmare for so many families," Britt said in the speech.…