ANKENY, Iowa — Former Vice President Joe Biden ignored his Democratic rivals and focused extensively on attacking President Donald Trump at a campaign event, saying Trump is "a commander-in-chief who has no notion — none — of what it takes to lead."

Biden mocked Trump for saying he was the one who protected pre-existing conditions and portrayed Trump as a divider who has bashed the press and Congress. In the 2020 election, Biden said, "the character of the country is on the ballot. The character of our candidates is on the ballot."

Biden’s Jan. 25 event attracted about 300 voters on a near-freezing evening to the John Deere Exhibition Hall at Des Moines Area Community College in Ankeny. Ankeny is a northern suburb of Des Moines.

PolitiFact is traveling through Iowa this week to fact-check Democratic caucus candidates. The home stretch leading up to the Feb. 3 caucus coincides with Trump’s impeachment trial in the Senate. Biden made a vague reference to the trial, saying that Trump has "gone after my family."

RELATED: We analyzed the stump speeches of Pete Buttigieg, Amy Klobuchar, Bernie Sanders, Elizabeth Warren and Joe Biden.

Biden told the crowd a few statements that we wanted to fact-check.

"Fact check this — fewer people have signed up to take the foreign policy exam to become a foreign policy officer than at any time in history."

This captures the general trend, though Biden exaggerated some of the details revealed in an NBC News report last year.

First, he’s referring to the Foreign Service Officer Test, which is offered to aspiring diplomats three times a year.

NBC News reported that the number of test-takers had dropped to its lowest point since 2008.

The data only went back to late 2007, so it did not reflect "any time in history," as Biden said.

That said, the downward trend has accelerated since Trump was elected.

Between October 2017 and October 2018, the network reported, 8,685 people took the test, a 22% decline from a year earlier. The number has been falling since fiscal year 2013, when 21,069 people took the test.

"Let’s be clear about something. 400,000 of our warriors — Americans troops — in these two wars (Afghanistan and Iraq) have suffered traumatic brain injury."

This is close to what Defense Department statistics show. The department found 413,858 service members were diagnosed with traumatic brain injuries worldwide between 2000 and the third quarter of 2019. Not every case stemmed from battlefield injuries in Afghanistan and Iraq.

The majority of these injuries are classified as "mild TBI, also known as concussion," the department said. Most service members were back on regular duty after a week or 10 days.

"Service members can sustain a (traumatic brain injury) during day-to-day activities, such as while playing sports or participating in recreational events, military training and military deployment," the Defense Department report said.

Says that Trump said of a judge who had ruled against him, we "can’t trust him because his father is Mexican."

This paraphrases what Trump said about U.S. District Judge Gonzalo Curielo in 2016.

Curiel, who was appointed to the federal bench in San Diego by President Barack Obama, was born and raised in Indiana. His parents were naturalized U.S. citizens from Mexico.

On June 2, 2016, Trump told the Wall Street Journal that Curiel had "an absolute conflict" in presiding over the Trump University litigation given that he is "of Mexican heritage" and a member of a Latino lawyers’ association.

The next day on CBS’ Face the Nation, host John Dickerson repeatedly asked Trump why Curiel’s Mexican heritage was relevant.

"He is a member of a club or society, very strongly pro-Mexican, which is all fine," Trump replied. "But I say he's got bias. I want to build a wall. I'm going to build a wall. I'm doing very well with the Latinos, with the Hispanics, with the Mexicans, I'm doing very well with them, in my opinion."

Trump’s attack on the California La Raza Lawyers Association of which Curiel was a member rated Mostly False. The group focuses on broad Latino issues and civil rights but had stayed out of the recent immigration debate.

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