In America, parties enter periods of hegemony when they are seen as having resolved the crisis of the age.
Lincoln, the first Republican president, reunited in blood a Union that had sundered over his election and a Southern rebellion against the ascendancy of an industrializing North.
With the crushing of the Confederacy by the armies of Sherman and Grant, the assassination of Lincoln on Good Friday, 1865, and the abolition of slavery, the Republican Party appeared to have solved the crisis of the age. The GOP owned the patriotism issue, "waving the bloody shirt," and the morality issue, emancipation, and thus became America's Party.
From 1860 to 1932, the GOP produced 13 presidents, three of whom were assassinated. Democrats gave us only two, Cleveland and Wilson, both of whom owed their election to divisions within the Republican Party.
By 1930, however, the nation was mired in the Depression. The architects were not Smoot and Hawley, but, as Milton Friedman proved, the faceless men of the Federal Reserve.
Easy money had overheated the economy and sent stock prices into the stratosphere. In 1929 came the Crash. Margin calls went out. Savings were withdrawn to meet them. Banks collapsed. With no deposit insurance, savings were wiped out and a third of our money supply vanished. The Fed failed to replenish it.
To the rescue in 1932 came "Dr. New Deal." Though the great medicine man failed to heal the economy -- unemployment was 17 percent in 1937 -- FDR was seen as a leader of energy and ideas doing his best to rescue a nation plunged into Depression by corporate greed.
His act had about run out its course when war came, and though he campaigned in 1940 as Wilson had in 1916, on a pledge to keep us out of war, FDR steered us directly into the world storm. Then, like Lincoln, he died within days of victory, as the United States emerged as liberator and savior of Western Europe and first power on earth.
The Democratic ascendancy from 1932 to 1968 gave us four Democratic presidents -- FDR, Truman, Kennedy and Johnson -- while the GOP elected only the war hero Eisenhower. Democratic dominance of the Congress was even more pronounced. From 1930 to 1980, a half-century, Democrats held the Senate and House for 46 years.
What destroyed the New Deal coalition was liberalism's failure to cope with the crises of the 1960s: crime, Vietnam, and a moral and cultural revolution in which Democrats had a foot in both camps.