WASHINGTON - Former U.S. Vice President Joe Biden is the leading Democratic presidential contender among two dozen candidates looking to take on President Donald Trump in the 2020 election, but Biden is proving to be unchallenged at committing verbal gaffes on the campaign trail.

Biden, with four decades on the American political scene, has long been afflicted with jumbling his public pronouncements into word salads that leave listeners guessing as to their meaning and political opponents quick to attack the 76-year-old politician.

The latest instances have come in the Midwest farm state of Iowa, where many of the crowded field of Democrats have trekked to the annual state fair to eat pork on a stick, a local favorite, aim their verbal attacks at Trump and look for votes ahead of the first Democratic presidential nominating contest early next February.

"We choose science over fiction. We choose truth over facts," Biden declared, as he attacked Trump from a newspaper's political soap box stand for the Democratic candidates.

Trump was quick to belittle Biden, for 36 years a U.S. senator, eight years former President Barack Obama's second in command and twice an unsuccessful presidential candidate.

"Does anybody really believe he is mentally fit to be president?," Trump said on Twitter. "We are 'playing' in a very big and complicated world. Joe doesn’t have a clue!"



Joe Biden just said, “We believe in facts, not truth.” Does anybody really believe he is mentally fit to be president? We are “playing” in a very big and complicated world. Joe doesn’t have a clue! — Donald J. Trump (@realDonaldTrump) August 10, 2019

As he left Washington for a vacation at his golf resort in New Jersey on Friday, Trump contended, "Joe Biden is not playing with a full deck."

To be sure, Trump often exaggerates his claims, with some U.S. media outlets saying he lies outright and have called him a racist after saying recently that four congressional lawmakers, all women of color, should "go back" to their home countries, even though all are American citizens, three by birth and one, a Somali refugee, a naturalized citizen.

President Donald Trump talks to reporters on the South Lawn of the White House, Aug. 9, 2019, in Washington.

In a White House statement last week, Trump, in condemning two mass shootings that killed 31 people, offered prayers for "those who perished in Toledo," not Dayton, Ohio, a city 240 kilometers away, where one of the mass shootings occurred.

But Biden mangled the geography even more, telling one crowd the first mass killing had occurred in Houston, Texas, instead of correctly pinpointing El Paso, Texas, and that the second ambush of innocents occurred in Michigan, a neighboring state of Ohio, but a two-plus-hour drive from Dayton.

Democratic presidential candidate former Vice President Joe Biden speaks at the Presidential Gun Sense Forum, Aug. 10, 2019, in Des Moines, Iowa.

In Iowa, Biden, talking about education in America, told voters, “We have this notion that somehow if you’re poor, you cannot do it. Poor kids are just as bright, just as talented, as white kids,” leaving the impression that black children were poor.

He quickly clarified: “Wealthy kids, black kids, Asian kids — no I really mean it, but think how we think about it.”

During the second round of Democratic presidential debates last month, Biden fumbled how much longer Trump could serve as president, if he is re-elected, suggesting it could be eight more years, when it could only be four more.

Then, as a finale, Biden urged voters who wanted to help his campaign to “go to Joe 30330 and help me in this fight."

But there was no such web site, although one tech-savvy rival quickly created one to divert fundraising to its campaign by using the "Joe 30330" web address.

Biden, as it turned out, had meant to tell would-be supporters to text him at that number.

Whether Biden's verbal slip-ups matter is an open question, with national surveys continuously showing him defeating Trump in hypothetical matchups next year, an outcome that would make Trump the country's first single-term president in nearly three decades.

At least one Democratic presidential candidate, Montana Governor Steve Bullock, now low in the polls compared to Biden, noted his misstep on educational attainment.

“It was wrong. As a frontrunner, if we want to beat Donald Trump, we’ve got to get it right," Bullock told the political news site Politico. "Everybody makes mistakes, but we can’t afford those gaffes if we want to beat Donald Trump.”