There are, right now, men in the USA who are denied the right to vote just because they are men

Consider an immigrant who applies for citizenship, having never registered for Selective Service.

1. If they're a woman they can become a citizen and vote, no questions asked about Selective Service
2. If they're a man they will be denied citizenship and therefore the right to vote on grounds of failing to register as a man. They will have to register and wait 5 years before reapplying

Remember this the next time someone says meaningful discrimination against men doesn't exist.