You're right to say I can't quote Jefferson on Islam because no such quote made it into history lessons on the founding of our nation. A quick google search shows Jefferson considered Islam, as well as Judaism and Catholicism, as part of deciding against making this a Protestant nation. While he didn't care for Islam himself, and it could be because he was a Protestant or an atheist, doesn't matter. We've had close relations with Islamic countries since that time without much weight put on what Jefferson thought. The trouble with Islam over the last forty years is what's being exploited now by Putin. And we just elected a president with soft targets all over the world that have his name on them.