”The usual rule is this: when Democrats win elections, they wield power. When Republicans win elections, they seek, or at least agree to, compromise.”
I will take it a step further and state the Democrats know how to leverage power, in the form of transient electoral majorities, for their long-term strategic advantage. To paraphrase Rahm Emmanuel, the Democrats do not let a majority go to waste.
The great historical examples of the past 100 years are FDR’s New Deal and LBJ’s Great Society, each enacted after electoral landslides that conferred Democratic control over the White House, Senate, and House. Social Security and Medicare, enacted during the New Deal and Great Society, are the twin colossi of the welfare state both in terms of dollar amounts and their political invulnerability. With their existence, the Democrats gain a structural political advantage over the Republicans.