Kimberly Guilfoyle, a fundraiser for former President Donald Trump’s 2020 campaign and girlfriend of Trump’s eldest son, Donald Trump Jr., announced on Monday morning that she would join Eric Greitens’s campaign for Senate as the national chair. “Governor Greitens is a fighter who has stood with President Trump and has a proven record of advancing conservative America First policies,” Guilfoyle said in a statement. “I am proud to join this team as the National Chair and look forward to championing Governor Greitens’s vision throughout Missouri and around the country.” Greitens, a former Navy SEAL and Missouri Governor, launched his campaign on March 22 for the U.S. Senate seat to be vacated by the retiring Sen. Roy Blunt (R-Mo.). “Proud to announce @KimGuilfoyle has joined our campaign as National Chair!” Greitens wrote on Twitter Monday. “She has been one [of] President Trump’s fiercest defenders, and she will continue to fight and defend …