People across the United States woke up to the news this morning about Georgia electing two Democratic senators. Although there are, and will be, many takes about the meaning of the election, one thing stands out to me: things can change rapidly.

For the past two decades, statewide elections in Georgia have been solidly Republican. Twenty years ago, George W. Bush beat Al Gore in Georgia by double-digit margins. Until 2020, the closest a Democratic candidate had come was a 5-point margin in 2016. But, then in 2020, Joe Biden defeated Donald Trump by nearly 12,000 votes. For a Democrat to win a senate race in Georgia was nearly unthinkable in the 2000s and 2010s. The closest a Democratic candidate got to winning was in 2002, when Saxby Chambliss won by a nearly 7 point margin. And yet, yesterday, two Democratic candidates won.

Yesterday reminds me of a lesson I learned about politics a long time ago, that of “punctuated equilibrium.” The concept, based in evolutionary biology and imported into policymaking theory in the book Agendas and Instability in American Politics, posits a feature of our government is that change happens, and sometimes it happens rapidly:

Our primary thesis is that the American political system, built as it is on a conservative constitutional base designed to limit radical action, is nevertheless continually swept by policy change, change that alternates between incremental drift and rapid alterations of existing arrangements. During quiet periods of policymaking, negative feedback dominates; policy innovations seldom capture the imagination of many individuals, so change is slow or rare. During periods of rapid change, positive feedback dominates; each action generates disproportionately large responses, so change accelerates. Critical points occur before the initiation of a positive-feedback process; such periods are referred to as windows of opportunity. Punctuated equilibrium, rather than stability and immobilism, characterizes the American political system.

Yesterday’s results sure seem to support that thesis.