Sen. Ron Johnson, R-Wis., who is running against Democratic Senate candidate Russ Feingold in the November election, has said he supports but does not endorse Donald Trump. Scott Applewhite / Associated Press

Wisconsin Republican Sen. Ron Johnson says Donald Trump should apologize for disparaging the bereaved parents of U.S. Army Capt. Humayun Khan, a Muslim who was awarded a Bronze Star after he was killed in 2004 in Iraq.

Johnson had earlier praised the Khan family in a statement that did not mention Trump. He went further in an interview Wednesday on WTMJ Radio, calling for Trump to apologize.

But Johnson refused to withdraw his support of Trump. Johnson was asked what it would take for him to no longer back Trump. He said the election is a binary choice and Trump is preferable to Democrat Hillary Clinton. Johnson said her handling of the Benghazi attack and use of a private email server while secretary of state has “completely disqualified” her from being president.

Clinton ad slams Trump with fellow Republicans’ own words

A new ad supporting Hillary Clinton uses the words of Republican leaders to make the case that Republican nominee Donald Trump is unfit to lead the United States.

The 30-second spot shows clips of 2012 Republican nominee Mitt Romney, former Secretary of Defense Robert Gates, former CIA Director Michael Hayden and other Republicans questioning Trump’s temperament and foreign policy experience.

Trump’s comments “create a clear and present danger,” says Hayden.

The spot was released by Priorities USA, a Super PAC supporting Clinton. Super PACs can raise unlimited amounts of money, but aren’t allowed to coordinate with campaigns.

The ad is running in nine battleground states.

Trump spokeswoman blames Obama, Clinton for 2004 death of Army captain

A spokeswoman for Donald Trump has blamed Barack Obama and Hillary Clinton for the 2004 killing of U.S. Army Capt. Humayun Khan in Iraq — even though the death occurred more than four years before Obama became president.

Trump has been in a public fight with Khan’s parents after Khan’s father criticized the Republican nominee at last week’s Democratic convention.

In an interview with CNN’s Wolf Blitzer Tuesday evening, Katrina Pierson said, “It was under Barack Obama and Hillary Clinton that changed the rules of engagements that probably cost his life.”

Obama was a state senator in Illinois in 2004. Clinton was a senator representing New York. She voted in favor of the Iraq War in 2002.

Trump has been widely criticized, including by many Republicans, for denouncing the Khans, who are Muslim-Americans.

Pierson’s comments have become a trending topic under #KatrinaPiersonHistory. She touched on the controversy herself on Twitter by writing that she’ll make history by getting Trump elected president.

Trump touts ‘great unity’ in his campaign

Donald Trump says there’s “great unity” in his campaign —despite growing dissent and turmoil among his fellow Republicans.

Trump tweeted Wednesday that the campaign unity is “perhaps greater than ever before.”

That comes as he continues to face criticism from Republican lawmakers for attacking the Muslim-American parents of a U.S. Army captain killed in Iraq. The soldier’s father had criticized Trump at last week’s Democratic convention.

On Tuesday, Meg Whitman, a prominent Republican fundraiser and former Hewlett-Packard executive said she would back Democrat Hillary Clinton. Also, Rep. Richard Hanna of New York became the first Republican member of Congress to say he will vote for Clinton.