Vice presidential candidate Sen. Tim Kaine highlighted the Sept. 11, 2012, terrorist attacks in Benghazi, Libya, for a second time this week as he argued Wednesday that Hillary Clinton is better qualified than GOP nominee Donald Trump to take the White House.

"Did you see Hillary interrupt her campaign and start to go after grieving parents who had lost somebody on an attack one of our embassies? No, because she has the heart of sympathy for people who've lost – she's not going to go after them. She feels for them. I've talked to her about it," the Virginia senator said at a campaign rally in Cedar Rapids, Iowa.

"She feels Benghazi very personally because Chris Stevens, the ambassador, was somebody she knew very, very well. But she wouldn't go after somebody who criticized her. That is beneath what a president does," he added.

Like his remarks earlier this week on the deadly 2012 attacks, Kaine's comments were totally unprompted. They were also made in reference to Trump's ugly spat with a Gold Star family of Muslim faith.

Khizr Khan, an American Muslim whose son, Army Capt. Humayun Khan, died in 2004 while serving in Iraq, rebuked the GOP nominee's immigration platform during a speech last month at the Democratic National Convention in Philadelphia.

With his wife by his side, Khan challenged Trump to read the U.S. Constitution.

The Republican presidential candidate and his supporters have responded to the speech with a series of attacks, including demands that the Gold Star family apologize and suggestions that Khizr Khan may have ties to Islamic jihad.

At the GOP convention in Cleveland, Patricia Smith, whose son Sean died in the 2012 attacks, delivered an address in which she said Clinton "should be in stripes" for her handling of the terrorist event.

On Wednesday, Kaine highlighted the difference between how Trump has responded to Khan and how Clinton has responded to Smith.

"In the Republican convention in Cleveland, they just put up one speaker after the next to trash Hillary Clinton, and they put up parents and family members of people who had lost their lives in the attack on our consulate in Benghazi, Libya," he said.

But has Clinton attacked the families of the Benghazi victims? Of course not, Kaine said Wednesday.

"Hillary's classier than that. Hillary's smarter than that. Hillary's more compassionate than that. Hillary has better judgment than that," he said.