Medal of Honor recipient Dakota Meyer, whose mother-in-law is 2008 Republican vice presidential nominee Sarah Palin, on Tuesday joined the chorus of military veterans and families condemning GOP presidential nominee Donald Trump’s attacks on the parents of a slain Muslim-American Army officer.

If @realDonaldTrump wants to be the Commander in Chief, he needs to act like one. And that cant start until he apologizes to the Khans. — Dakota Meyer (@Dakota_Meyer) August 2, 2016

Meyer on Twitter called on Trump to apologize to Khizr and Ghazala Khan, whom Trump has attacked since Thursday, when they appeared at the Democratic National Convention to criticize Trump’s anti-Muslim rhetoric and policy proposals.

Meyer, while serving in the Marine Corps in 2009, risked his life to save 36 American and Afghan troops in a Taliban-controlled area in Afghanistan. President Barack Obama awarded him the Medal of Honor ― the highest military decoration ― in 2011.

Veterans, as well as prominent GOP lawmakers, have widely denounced Trump’s insults of the Khans. Palin’s 2008 running mate, Sen. John McCain (R-Ariz.), a prisoner of war in Vietnam, issued a lengthy statement on Monday criticizing Trump. However, both McCain and Palin continue to back Trump’s candidacy.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.