100 years is way too optimistic. No one can tell what will happen 100 years from now. Imagine how different the world looked 100 years ago.
The US is going to face a major demographic shift by 2040. From that point on, it will no longer be a White country, it will be a multi-racial country and will look increasingly like Brazil demographically. Whites will likely still occupy an outsized and disproportionally influential place however.
With the exponential rate at which technology is proceeding, anything can happen. If the US cannot keep up with innovation, China can seize the winning heights within 5 years as it is pouring endless resources into it and has far more competent leadership than the US.
However, again, 100 years from now, no one can figure out what would happen. China may become the leading superpower 50 years from now and then decline 80 years from now. India may get its act together and become a superpower 70 years from now. Who knows.