In Florida felons have to pay off all their fines in order to regain their right to vote. An organization is offering to pay off the fines of Florida felons so they can vote. Some people are claiming that this violates 18 U.S. Code § 597 (Expenditures to influence voting):
Whoever makes or offers to make an expenditure to any person, either to vote or withhold his vote, or to vote for or against any candidate;
It seems to me that this is not a violation of that law, since the organization neither requires that the felon vote for a specific candidate nor even that they vote at all. However, I am not a lawyer.
There's also the Florida law Title IX Chapter 104 Section 061 (2):
No person shall directly or indirectly give or promise anything of value to another intending thereby to buy that person’s or another’s vote or to corruptly influence that person or another in casting his or her vote.
Again, I don't think that paying to enable someone to vote is either buying that person's vote or corruptly influencing that person, but again I am not a lawyer.