What would you say had a Muslim President of the United States said 'We are all created by Allah" or a secularist President said "We are all created by the same swamp muck"? Or can I guess your response? He made an establishment statement in a joint session of congress, not some remark to Westerboro Baptist that no one else heard.
It's unconstitutional.
Doesn't the 1st Amendment allow him to say something unconstitutional?