US President-elect Donald Trump on Sunday named Lebanese-American businessman Massad Boulos as his senior advisor on Arab and Middle Eastern affairs, the latest family member to be appointed to a key position.

“I am proud to announce that Massad Boulos will serve as Senior Advisor to the President on Arab and Middle Eastern affairs,” Trump posted on Truth Social of the appointment, which puts his daughter Tiffany’s father-in-law in a major White House position.

Boulos was a key emissary for the Trump campaign, helping to mobilize Arab American and Muslim voters, many of whom were angry over President Joe Biden’s steadfast support for Israel in the Gaza war even as the civilian death toll rose into the tens of thousands.

The businessman will take over a difficult portfolio, with Israel’s war still raging in Gaza, a fragile ceasefire between Israel and Hezbollah in Lebanon seeing early violations, and rebel forces in Syria making advances against the government of Bashar al-Assad.

Boulos’ son, Michael, is married to Trump’s daughter Tiffany.

On Saturday, Trump named real estate executive Charles Kushner — the father of his son-in-law Jared — as his pick to be the US ambassador to France, the latest case of Trump eschewing experience or expertise as the criterion for joining his team.