The political analyst Samuel Lubell introduced the concept of the sun and moon parties in 1951. The sun party is the majority party, and “it is within the majority party that the issues of any particular period are fought out; while the minority party shines in reflected radiance of the heat thus generated.”
Franklin D. Roosevelt’s Democratic Party was the sun party for two generations, until the dawn of the Reagan majority. When Bill Clinton signed welfare reform and (falsely) declared, “The era of big government is over,” he was reflecting the reality of that transformation.
In the early 2000s, the GOP receded back into moon status. “But,” as David Brooks noted in 2011, “something strange happened. No party took the lead. … Both parties have become minority parties simultaneously. We are living in the era of two moons and no sun.”
That dynamic only intensified as politicians and voters accepted the new abnormal as normal. If you look too closely at specific elections, it can be hard to see, but the trend becomes clear in retrospect.
George W. Bush ran in 2000 as a sun party candidate and eked out the slimmest of victories. As it happens, the use of “red” and “blue” to denote Republicans, Democrats and the states’ political complexions also became a fixture of our politics that year. It may seem like a trivial thing, but I think red-vs.-blue rhetoric accelerated polarization by solidifying the idea that partisanship is a kind of identity.