What kind of campaign did Calvin Coolidge run to win the presidency?

Calvin Coolidge ran a safety first campaign. The President was popular; the economy was doing well and most Americans felt pretty good with how things were going. There was no need, then, for anything radical from the Republicans—just four more years of the same policies that had proved generally popular with the American people.
Coolidge's campaign slogan "Keep cool with Coolidge" summed up the Republicans' approach. Coolidge was presented as a safe pair of hands, someone who could be relied upon to offer firm, steady leadership in an uncertain world. The Democrats made things a lot easier for the Republicans by choosing a complete nonentity, John W. Davis of West Virginia, as their presidential candidate. Davis's personality was even less forceful than that of the incumbent and so he didn't provide the American people with a particularly compelling reason to come out and vote for him. Instead, they opted for Coolidge in overwhelming numbers, showing their support for his steady leadership and largely successful economic policies.