Ramesh Ponnuru: Why Republicans fear challenging Trump in 2020
FILE - In this Oct. 2, 2018, file photo, President Donald Trump arrives to speak at a campaign rally at the Landers Center Arena in Southaven, Miss. (AP Photo/Evan Vucci, File)
FILE - In this Oct. 2, 2018, file photo, President Donald Trump arrives to speak at a campaign rally at the Landers Center Arena in Southaven, Miss. (AP Photo/Evan Vucci, File)