WASHINGTON — In the first days of January 1960, Democratic Sen. John F. Kennedy of Massachusetts declared his candidacy for president, nearly a year before the actual balloting. This year, at least half a dozen hopefuls have already signed on for what promises to be an exhausting and costly fight for the office in 2020, with more to come.

Kennedy’s early start served him well, as did the political calendar. It brought him a clear victory in the first primary in neighboring New Hampshire, followed by successes in West Virginia and Wisconsin over Sen. Hubert Humphrey of Minnesota, and nomination in Los Angeles in August.

This time around, with no clearly obvious 2020 contenders beyond 76-year-old former Vice President Joe Biden and 77-year-old Sen. Bernie Sanders of Vermont, it seems as if everybody’s Democratic aunt or uncle is running.

An obvious inspiration is President Trump, whose chaotic first term inspires a very large field to try to unseat him. Democratic candidates are convinced that he is beatable next year, and that the country desperately needs to get him out of the Oval Office before he does much more damage.

The credible veteran Sen. Elizabeth Warren of Massachusetts has been joined by comparably little-known newcomers to the national stage as Sens. Kirsten Gillibrand of New York and Kamala Harris of California, as well as former Obama Cabinet member Julian Castro of Texas, who at least come from large-state bases.

Rep. Tulsi Gabbard of Hawaii has also committed to running. Others considering a run include Sen. Amy Klobuchar of Minnesota and former Rep. John Delaney of Maryland.

Perhaps the best indication that the Democratic nomination is wide open is last week’s entry of 37-year-old Pete Buttigieg, the mayor of South Bend, Ind., home of Notre Dame University.

He is running as an unabashed millennial, arguing that it’s time for the new generation to take charge. He offers a positive if thin resume of local political accomplishment.

Much of his chance will rest on his ability to capture the imagination of the young. But in this pitch, he already will have strong competition from former Texas Rep. Beto O’Rourke, boyish-looking at 46 and eloquent, who narrowly lost his bid to unseat Republican Sen. Ted Cruz.

Not surprisingly, Biden, who recently declared himself “the most qualified person” for the presidency after eight years as vice president and 36 years in the Senate, leads most early polls by a wide margin. But he is yet to decide on running, and he clearly is not the fresh face Buttigieg and other young hopefuls insist the party must choose, or lose, next year.

Wikipedia lists nearly 30 declared and musing Democrats, including Mayor Bill DeBlasio and former Mayor Michael Bloomberg of New York; Mayor Eric Garcetti of Los Angeles; Sens. Cory Booker of New Jersey and Michael Bennet of Colorado; Govs. John Hickenlooper of Colorado, Jay Inslee of Washington and former Virginia Gov. Terry McAuliffe.

In 2016, 15 Republicans offered themselves against the longshot Trump and were dispatched with insulting ease by him, including the early frontrunner, former Florida Gov. Jeb Bush. This time around, the GOP field may be much smaller, should Trump survive threatened impeachment and seek re-election. Retired Ohio Gov. John Kasich is one of the few Republicans poised to try again after being among those wiped out by Trump the first time.

The prospect of a bumper crop of presidential candidates in one or both major parties may be winnowed down quickly in the traditionally early state caucuses in Iowa and the New Hampshire primary. Losses there usually evaporate campaign contributions, and winning there doesn’t guarantee later nomination.

Warren, the first announced Democratic contender, has entered in New Hampshire, and Harris is kicking off in Iowa, in February 2020. The earliest Super Tuesday primaries ever in nine states including California, on March 3, 2020 could quickly level the playing field.

But in the era of Donald Trump or its uncertain aftermath, punditry’s crystal ball is especially cloudy right now.

Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books. You can respond to this column at juleswitcovercomcast.net.