How would life be different if your U.S. citizenship rights were gone?
This depends very much on the degree to which our rights were being taken away.
If our rights were taken away in a small way, we would not be affected much. If, for example, the 4th Amendment simply did not exist, our lives would not likely be affected in a big way. Having never committed a crime, I would not worry a lot about searches and seizures. This would not change my life much.
But if our rights were taken away in a very serious way, things would really change. Let us imagine that the US truly became a police state with the police aggressively harassing us. Imagine that the government would censor our every web posting or search as the government does in China. If this were the case, our lives would be changed dramatically. We would live in a situation where everything we did could be monitored by the government and controlled.
The answer to this, then, depends to a great degree on whether the government really tried to completely take our rights away.
Your question does not make clear whether you are posing a hypothetical involving citizens versus non-citizens or a hypothetical suspending the rights all of us have at the moment. Certainly, non-citizens have no right to vote, but the United States Constitution protects them in most ways, too. If we are talking about a suspension of the Constitution, as the first response suggests, he correctly points out that we have no idea with what that document would be replaced, if it were to be replaced at all, or if we would simply have no government and complete anarchy. Certainly, it is a valuable exercise to contemplate a suspension of rights, which allows us, I hope, to value what we have and protect it.