(L/R) US Senate Majority Leader John Thune, Republican from South Dakota, walks with Senator Lindsey Graham, Republican from South Carolina, on their way to the Senate Chamber at the US Capitol in Washington, DC, on June 4, 2026. President Donald Trump's agenda faces a series of tests in the US Senate on Thursday, as lawmakers began a marathon amendment process on a $70 billion immigration enforcement bill after weeks of Republican anxiety over some of his most contentious policy moves. (Photo by Kent NISHIMURA / AFP via Getty Images)