Nothing in capitalism prevents a country from prioritizing its own citizens.
And it is uncontroversial in most countries that a country should do this.
So this isn't a contradiction. Indeed america is capitalist. And it is also prioritizing its own citizens. There is nothing weird about that.
Most capitalist countries have 100% employment for their citizens and little to no immigration? No. "Every citizen who can work having a job" is not something capitalist countries do. They all take ample advantage of foreign labor, they all have corporations that prioritize their own profits and outsource.