Before launching a broadside against Sen. Tammy Duckworth (D-Ill.), Fox News host Tucker Carlson acknowledged that it’s not easy to go after a Purple Heart recipient who lost both her legs while serving her country in Iraq.

“You’re not supposed to criticize Tammy Duckworth in any way because she once served in the military,” Carlson said Monday night.

That didn’t stop him from calling Duckworth, a contender to be presumptive Democratic presidential nominee Joe Biden’s running mate, “a deeply silly and unimpressive person” and suggesting that she and other Democratic leaders “actually hate America.”

Duckworth quickly jabbed back on Twitter, writing, “Does @TuckerCarlson want to walk a mile in my legs and then tell me whether or not I love America?”

With Duckworth’s profile rising as a potential Biden running mate, Carlson’s attack offers a preview of what could come as Republicans gear up to go after whomever the former vice president chooses to join his ticket, as The Washington Post’s Sean Sullivan reported.

Duckworth’s combat experience has helped her ascend a list of Biden’s potential running mates, The Post reported. In 2004, she lost her legs when insurgents shot down the Black Hawk helicopter she was co-piloting with a rocket-propelled grenade.

After her election to the Senate in 2016, she’s used her military record to rebuke Republicans who have questioned Democrats’ patriotism. When Rep. Douglas A. Collins (R-Ga.) in January accused Democrats of being “in love with terrorists,” Duckworth retorted that “I left parts of my body in Iraq fighting terrorists.”

On Monday, Carlson went after Duckworth for an interview with CNN’s Dana Bash over the weekend, when the senator suggested a “national dialogue” over whether monuments honoring George Washington should be removed because he owned slaves.

“When Duckworth does speak in public, you’re reminded what a deeply silly and unimpressive person she is,” Carlson said before playing the clip.

The Fox News host then suggested that he is loath to question anyone’s patriotism, saying, “It’s a very strong charge, and we try not ever to make it.”

“But in the face of all of this, the conclusion can’t be avoided. These people actually hate America,” Carlson said. “There’s no longer a question about that.”

Later in the segment, Carlson argued that “the leaders of today’s Democratic Party … despise this country.”

Carlson, who has endured numerous calls for advertisers to boycott his show over his statements on race and the protests that followed George Floyd’s death in late May, faced quick criticism for questioning Duckworth’s patriotism.