I think a lot of evangelicalism has gnostic tendencies. But labelling is only of limited value, I think, and of course you won't get very far saying this to them directly. Still, I know that I see a lot of Gnosticism in the kind of Christianity I was taught (invisible Church, sacraments are unimportant, personal illumination is everything, etc.).
Having said that, not all Protestants are like this. Perhaps all share these tendencies to some degree, but in fact the first place where I heard my family's kind of Christianity described as "Gnostic" was at the college I attended run by the "Christian churches and churches of Christ."