Trump has persuaded Perdue to join a race that, as recently as this summer, he promised he would not enter. The result is that Georgia Republicans face an expensive and backward-looking primary fight. The only issue separating Kemp and Perdue is the 2020 election. Kemp wants to move forward; Perdue is the champion of relitigating the past. The big winner of Perdue’s announcement is Democratic candidate Stacey Abrams, another politician incapable of admitting she lost. With Trump’s help, however, she may finally win.