As the presidential contest enters the final sprint, campaign aides and allies close to Vice President Kamala Harris are growing cautiously optimistic about her chances of victory, saying the race is shifting in her favor. Top Democratic strategists are increasingly hopeful that the campaign’s attempts to cast former President Donald J. Trump as a fascist — paired with an expansive battleground-state operation and strength among female voters still energized by the end of federal abortion rights — will carry Ms. Harris to a narrow triumph. Even some close to Mr. Trump worry that the push to label him a budding...