Trump slams Joe Biden as 'mentally weak,' calling him '1 percent Joe' and saying he's 'slower than he used to be'

• President Donald Trump slammed Democratic frontrunner and former Vice President Joe Biden as "a dummy," "mentally weak," and "1% Joe" in Tuesday remarks on the White House's South Lawn.
• Trump made the remarks on the White House lawn just before departing for Iowa, where he and Biden will each hold campaign events over the next few days.
• Trump later said he would rather run against Biden than anyone else in the field, continuing, "I think he is the weakest mentally. I like running against people that are weak mentally."
• In Biden's planned remarks for a Tuesday speech in Iowa, the former vice president directly attacks Trump, calling him "an existential threat."
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President Donald Trump slammed Democratic frontrunner and former Vice President Joe Biden as "a dummy," "mentally weak," and "1% Joe" - an insulting reference to Biden's past performances in the 1988 and 2008 Democratic primaries.

Trump made the remarks on the White House lawn just before departing for Iowa, where he and Biden will each hold campaign events over the next few days. While Trump will visit an ethanol plant and attend a reception in Council Bluffs, Biden will campaign in Eastern Iowa, according to the Washington Post.

"I heard Biden, who is a loser - I mean, look, Joe never got more than 1%, except Obama took him off the trash heap. Now it looks like he is failing. It looks like his friends from the left are going to overtake him pretty soon," Trump said, adding of Biden: "he looks different than he used to, he acts different than he used to, he's even slower than he used to be."

Trump later said he would rather run against Biden than anyone else in the field, continuing, "I think he is the weakest mentally. I like running against people that are weak mentally. I think Joe is the weakest up here ... I think Joe is a man who is - I call him 1% Joe. Until Obama came along, he didn't do very well."

Read more: Trump reportedly calls up his old associates at night to rail against Joe Biden, who he thinks is 'too old'

In Biden's planned remarks for a Tuesday speech in Davenport, Iowa, the former vice president directly attacks Trump, calling him "an existential threat" to America and slamming him over the tariffs on China and the European Union that Trump has levied.

"Any beginning econ student at Iowa or Iowa State could tell you that the American people are paying his tariffs. The cashiers at Target see what's going on. They know more about economics than Trump," Biden will say, according to the Washington Post.

In his comments on the South Lawn, Trump hit back on Biden on trade issues, calling him "a dummy" over Biden's previously-stated skepticism of China's threat as an American adversary.

But in Biden's Tuesday speech, he aggressively takes the fight back to Trump, with his planned remarks saying, "we need to get tough with China. They are a serious challenge to us, and in some areas a real threat. And every single step that Donald Trump is taking is only exacerbating the challenge."