Well, Coolidge was right as he died due a heart attack in 1931. This led to disastrous Presidency of bank scandal-plagued Charles Dawes, who was impeached and barely acquitted by Senate. Tensions raised after Bonus Army Massacre and they were fundamental to push progressive democrats to bolt after Al Smith's nomination, running under Progressive Party banner and with Burton Wheeler as candidate. Huey Long's candidacy in 1936 was able to win South and Midwest and split the vote allowing to a discredited Republican Party to make a comeback with Herbert Hoover (that was the Long's plan in order to replace Democratic Party as Republican's adversary). Progressives were then able to renew themself under Henry Wallace's leadership after Long assassination, winning White House in 1968 for the first time against Republican Vice-President William Fife Knowland from California and Dixiecrat candidate George Corley Wallace in a historical victory for Progressive candidate Eugene McCarthy who put an end to thirty-two years of Republican rule. No Coolidge, no Dawes, no bolting and maybe a conservative and progressive democratic coalition could win in 1948 against Warren (maybe running under an unifying figure as a popular war hero, as Eisenhower, McArthur or Patton).