Tuesday's voting in the District of Columbia brought down the curtain on the ninth presidential primary campaign I've covered.
There's never been another like it — or even close.
A reality television star inexperienced in government, unfamiliar with policy, and unmoored from conventional norms of political behavior has managed to become the Republican Party's presumptive candidate. Donald Trump has done it while harshly insulting the last Republican presidents, the two previous Republican nominees, and every one his 2016 rivals.
Despite being the party leader, he continues to hold the GOP at arms length, referring to it as "they," not "we." Yet he has pulled off this hostile takeover by harnessing decades of anger, frustration and fear over America's changing demography, culture and economy. In the process, he has rejected such tenets of modern conservatism as international trade expansion and the need to curb massive government entitlement programs.
Democrats have selected the first woman to lead a major party ticket. That remarkable historical breakthrough feels less remarkable at the moment because of circumstances: Hillary Clinton has been a national figure for a quarter century from the time of Bill Clinton's 1992 campaign; she has been first lady, U.S. senator and secretary of state; she follows Barack Obama's history-shattering run as the first African-American president.
But Clinton has made history just the same.
Her triumph wasn't the only part of the Democratic contest that broke familiar molds. So was the success of the elderly, self-described socialist who tested her resilience. Bernie Sanders rode a sense of frustration and anger similar to the one that propelled Trump, albeit with a different audience.
The heavy baggage Clinton and Trump bring to the general election augurs a fall contest that's difficult to predict. In the modern presidential era, American voters have never faced a choice of two nominees who are so unpopular.
Trump's baggage appears heavier. Polls show him clearly behind. He continues nonetheless to relentlessly provoke — Democrats, fellow Republicans, the media, Hispanics, Muslims — in ways that raise questions about his ability to maintain control of the GOP.
Having failed to recruit a prominent third-party challenger to carry the banner of traditional conservatism, "never-Trump" Republicans now whisper of ways to stage a convention coup in favor of another nominee. Such an idea sounds outlandish because it it is so far removed from the experience of recent decades.
But 2016 is the election for which words like "unprecedented" are meant to be used. We have five months to watch, eyes wide open.