Whoa. I was being very generous. From my link, I thought the 13.2% was people who didn't answer. Undertoad's link lists them as Nonreligious/Secular, which is probably what I'd check.
So how about this?
76.5% recognise Jesus as divine.
Using God instead (generously) adds 5.5%.
Removing any religious message includes at least an additional 14.6%.
Can you support "under God" over "under Jesus" in order to include 5.5% more people, but 14.6% more aren't worth it?
(chances are, it's between 1.4% and 14.6%)