Thirteen Republican Senators Are Demanding President Trump Halt Immigration Enforcement At The United States-mexico Border Until They Can Pass Legislation Closing A Legal Loophole, Perhaps Leaving The Border Open For Years. Sen. Orrin Hatch (R-UT) Sen. John McCain (R-AZ) Sen. Pat Roberts (R-KS) Sen. Susan Collins (R-ME) Sen. Lisa Murkowski (R-AK) Sen. Bob Corker (R-TN) Sen. Lamar Alexander (R-TN) Sen. John Boozman (R-AR) Sen. Dean Heller (R-NV) Sen. Cory Gardner (R-CO) Sen. James Lankford (R-OK) Sen. Bill Cassidy (R-LA) Sen. Rob Portman (R-OH)