Mark Martin backs Donald Trump at rally: 'Build that wall!'

Republican presidential candidate Donald Trump addresses the media during a press conference on March 5, 2016 in West Palm Beach, Florida. Primary voters head to the polls on March 15th in Florida. / AFP / RHONA WISE (Photo credit should read RHONA WISE/AFP/Getty Images) HOMESTEAD, FL - NOVEMBER 16: Mark Martin, driver of the #14 Bass Pro Shops / Mobil 1 Chevrolet, stands in the garage during practice for the NASCAR Sprint Cup Series Ford EcoBoost 400 at Homestead-Miami Speedway on November 16, 2013 in Homestead, Florida. (Photo by Jeff Zelevansky/NASCAR via Getty Images)

Republican presidential hopeful Donald Trump was in Cabarrus County, North Carolina, stumping for votes in the same county that is home to Charlotte Motor Speedway.

Introducing Trump was former NASCAR driver Mark Martin, a strong supporter of the businessman and his campaign for the White House.