Is there any real difference?
Of course, the Deist’s recognize Objective Truth and Natural Law Theory which presupposes a Designer. Atheists are Relativists.
What that means is there can be no “homosexual” marriage—because there is a standard for Right and Wrong which comes from Natural Law (imbedded into our Constitution because our Natural Rights come from God.)
“Homosexual” marriage defies “Right Reason according to Nature” (Just Law) which is the fundamental principle of our Legal System.
So, there is a MAJOR difference between Deists and Atheists—and it is Rational Thought-—The Age of Reason was when “Deists” appeared.
Irrational Atheism led to Hitler, Stalin, Lenin, Mao, Pol Pot BECAUSE there is no Objective Truth—so any kind of law is “Right” —like homosexual marriage. There is no basis for Right and Wrong for atheists—just whatever urge feels right.