We live in an electoral system. For almost all of the states of the U.S. it's actually factually correct that there's no difference for whom you vote in the Presidential elections. In many locations, it also doesn't matter who you vote for in Congressional ones thanks to gerrymandering drawing boundary lines around you before you even get to the polls.

We can discuss ideologically what the differences are between the parties, but as those of us in CA, NY, NJ, etc. well know - it's purely academic.

[edit:] Folks, it's a winner-take-all capital-E Electoral system in the vast majority of states, and in the vast majority of states, the demographic votes consistently in the same way. Thus very few states swing the entire Presidential election process, meaning that they matter. In California, for example, 3 million Democrats could have stayed in bed all day and not voted at all, and still it would have not touched the end result there.