Khizr Khan, the gold-star father of a Muslim American soldier who died fighting in Iraq, first gained national attention by provoking Donald Trump with his pocket Constitution at the Democratic National Convention in July.Now, a few months after the feud between Trump and his family, Khan is back in a new emotional campaign ad for Hillary Clinton in which he asks the Republican nominee—and voters in the key battleground states where it's airing—a simple question: "Would my son have a place in your America?"In the ad, Khan revisits photos and military memorabilia that belonged to his son, Captain Humayun Khan, who was killed trying to shield his fellow troops from a suicide bomber."My son moved forward to stop the bomber. When the bomb exploded, he saved everyone in his unit," says a teary-eyed Khan. "Only one American soldier died. My son was Captain Humayun Khan. He was 27 years old, and he was a Muslim American."The ad ends with Khan's question for Trump, reminding viewers of the Republican nominee's hardline stance on an immigration ban on Muslims—even potential war heroes like Captain Khan. According to CNN, the ad will play in Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio, and Pennsylvania in the hopes of pulling more undecided voters over to the Democratic nominee before November 8.Read: We Asked Immigration Experts How Trump's Muslim Ban Would Actually Work