Sheldon Anderson, a prominent Jewish backer - who has donated billions to various Republicans for years AND who started a newspaper in Israel - has been pushing for this for a long time. For him, it serves as marker that the United States supports Israel over the Palestinians.
For many on the Evangelical right, it serves as the start of the time Second Coming. Sure it will kill hundreds of millions in the middle east, but it saves them. Yay.
For some people in America, with a persistent but low level of anti-Muslim bias, it is a way to poke the Muslim world with very little downside.
For most Americans it is a non-issue. Given everything else going on in the country, this is relatively unimportant to us as an issue.
For the "international community", it makes the US less able to be an independent arbiter of peace in the Middle East. But most foreign actors didn't ever think we independent arbiters before. For some international observers, it makes us subservient to Israel policies - but Americans don't care. We believe about foreigners in general "they hate us anyway - no matter what we do".
We are breaching international norms, and our own stated morality - but welcome to Donald Trump's America kids. Breaching our own morality is what we do now.