You can go ahead and try to measure the speed of light in a vacuum if you like. If your measuring instruments are properly calibrated by an atomic clock, then you are going to get 299,792,458 meters per second every time.
America must move into the future. The era of cheap oil, energy dependence, and "what me worry" climate science is over. The United States must join, not just the rest of the world, but the 21st century.