Could a convicted felon even vote again?

If s/he gets a pardon.
In some states, there are other possible procedures to get voting rights restored.

It's wrong to deny a citizen their right to vote after serving all their time. It's against the Constitution.

As a Conservative, I say that it is ridiculous that a person that fully pays their debt to society by serving their time and completing their parol are denied the right to vote anywhere in America.

In South Carolina they can once they serve their time and finish their parole.

In the US, it depends upon the state. It's currently a hot issue in Virginia, which has been working to restore voting rights to some ex-prisoners.

Yes anyone can vote except minors

Generally speaking, no.There are exceptions, but they cannot own firearms or vote.

Nearly ALL states have provisions to restore voting rights at some point. The process depends on the state, and ranges from automatic restoration when the sentence is completed, to a formal application X years after the sentence is completed.

The 15th

The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of race, color, or previous condition of servitude.

No.

They could, but it would be illegal.