Taking a reasoned approach may not be the best way to overcome religious objections to science teaching in the USA. I'm not American and Americans come across as very patriotic always talking about being "the greatest country in the entire history of the world..", well let educationalist play the patriotic card. It would go something like:

"Our economy is being overtaken, the Chinese space programme is more ambitious than ours, the Indians are taking over IT, Why? Because we insist on training our kids to be scientific morons." The American hegemony will go the way of all the others, Greek, Roman, British unless you keep ahead of the opposition. Portray the Republicans and the evangelists as un-american saboteurs, shouldn't be too hard considering it's true.

Whoops, there goes my argument, since when has truth been a force in US political and social life. Dammit!