Why are Christian Nationalists always the loudest?

Is there an sociological explanation behind it? Like,you would expect christians to be people that actually love thy neighbor, help the poor,etc.

But in America and some other parts of the world, you see christians using their faith as an excuse to discriminate people based on their sexual orientation and gender identity. Honestly, if Jesus ever visited the US ,he would be disappointed.

So why is it that Christian Nationalists are the loudest, and not the christians that actually follow the words of Jesus?