I would disagree that the New Testament is anti-wealth, Tony, it rather teaches that wealth and its acquisition should not be your be-all and end-all, and if it is, you have problems. One of the most misquoted verses in the New Testament is 1 Timothy 6:10:
For the love of money is a root of all kinds of evil. Some people, eager for money, have wandered from the faith and pierced themselves with many griefs.
Note, not money is the root of all evil (the common misquote) but the love of money. As a practical example, Paul's first convert in Europe was Lydia in Acts 16 - as a seller of purple cloth (purple, obtained only from certain types of sea shell, was incredibly expensive), she would have been a very wealthy woman. But she was "a worshipper of God", i.e. attracted to Judaism and its ideals, so her wealth and the acquisition wasn't the dominant value in her life. Jesus's challenge to the rich young ruler in Luke 18, and the subsequent statement that "it is easier for a camel to go through the eye of a needle [the small gate set into a larger city gate] than for someone who is rich to enter the kingdom of God" was a challenge to see where his values really lay.
So, what the New Testament is saying is not that wealth is bad, but that faith in Jesus is paramount, and anything that gets in the way of that fails the test of Christianity. Jesus uses extreme hyperbole in Mark 9 to illustrate this:
If your hand causes you to stumble, cut it off. It is better for you to enter life maimed than with two hands to go into hell, where the fire never goes out.
And if your foot causes you to stumble, cut it off. It is better for you to enter life crippled than to have two feet and be thrown into hell.
And if your eye causes you to stumble, pluck it out. It is better for you to enter the kingdom of God with one eye than to have two eyes and be thrown into hell,
In the very particular case of the USA, it appears to me to be a confusion of both conservative Christianity and the US's Old Testament view of itself, as a successor to ancient Israel, a nation uniquely founded by God as an example to the rest of the world, and punished for its national sins when it gets it wrong. (The Mormons believe that the Constitution is divinely inspired, even though none of the Founding Fathers were religious men). Then add on to that an extreme extension of what has been called the "Protestant work ethic", a continuation of the Calvinist belief in hard work and frugality. From this comes the very unbiblical view that being rich is actually a sign of virtue, and that being poor a sign of the lack of it. Charity and pity has no place in this world view, just judgmentalism.