Is this a good thing or bad? Does this contradict Jesus's message of love and peace?
The Left Wing in American' politics would hope to scare people into thinking Nationalism is on the rise. Nationalists have been active in America for a great many years. White Nationalists, Black Nationalists, like the Nation of Islam for example.
I wouldn't worry overmuch.
Is this a good thing or bad? Does this contradict Jesus's message of love and peace?
If Nationalism makes war more likely, it is bad. If Nationalism can act as a check on the power of global financial elites who effectively undermine national economies ability to provide for their own people, I think its more likely to be a good thing but could still have its share of drawbacks. I'm not sure what Jesus would say.
If the nation is Christian, then strong nationalism is necessary, nay, expected. We must never be ashamed of Christ and His cross. We must willingly embrace and promote our Christianity and defend it when it is criticized unfairly by the world.
nationalism is for all intents and purposes a symptom of mental disorders.
Wrong. There may be a slight chance that you may be opposed to American nationalism, founded upon Christianity, for obvious reasons.