For instance, in voting for who becomes the mayor of my city I have one vote. Nobody else has more than one vote. So in a sense, I’m equal with everyone else in choosing the mayor. On the other hand, there are some people with more money. They can pay for more ads and influence the choices of more voters than I can. There are some people who have a lot of political influence who can decide who to endorse and who to encourage not to run for office in the first place. Someone who has a political “machine” can offer endorsements, money, campaign workers, etc. to a candidate. In exchange, the candidate is expected to favor the interests of the politically powerful person. All I can do, basically, is offer one vote and a few dollars and maybe a little of my time for the campaign. This is an example of political inequality.

Then there’s the different weight given to votes based on the electoral college. There’s something called “disenfranchisement.” You can look both of those up.