Answer:
When Harry S. Truman ran for president in 1948, several factors supposedly were working against him: the media, Republican candidate Thomas E. Dewey's popularity, and Truman's own down-to-earth style.
Explanation:
Colons are used before a list of items, which in this case are the factors working against Harry S. Truman.
Quinton is a place name, a surname or a masculine given name. The place name originates from Old English cwen "queen" or cwene "woman" and tun "farmstead, estate".