You really don't see any difference between George W. Bush and John Kerry or Al Gore? You really didn't see any difference between Ronald Reagan and Walter Mondale or Jimmy Carter? You really thought Bill Clinton and Bob Dole were pretty much the same? Would Hubert Humphrey or George McGovern have been as politically able to open relations with China as Richard Nixon? Would the Civil Rights era or the Vietnam War have run the same course if Barry Goldwater had been elected in 1964 instead of Lyndon Johnson? If you answer "yes" to any of the above, do us all a favor on election day and stay home.
Not seeing a difference between Democrats and Republicans is like thinking Limburger cheese and a chocolate malt are pretty much the same because they're both dairy products, or filet mignon is pretty much like liverwurst because they're both meat.
Possibility 2: You Belong to the Lunatic Fringe
The other reason some people see the two parties as identical is they're out on the planet Mongo, so far from earth that even huge differences shrink to the vanishing point. These folks are so far removed from reality that they expect things that no rational political system can offer.
Rightists: get real. We are not going to pay off the national debt by selling poor people to be ground up for cat food. We are not going to divvy up the national parks for vacation homes, and even if we did, do you think you'd stand a chance of getting anything? We are not going to declare your particular cult (not denomination, cult) the State religion or round up the particular group you think are enemies of the State. We are not going to abolish taxes or go back to gold coins. So if you wonder why none of those ideas ever get a fair hearing, it's because they already have, and they flunk the most elementary common sense tests. Occasionally somebody in Washington thinks of one of those ideas, but once the pink rabbits go away, the shakes stop and the hangover quiets down to a dull throb, they get over it.
And you folks out in the weird antipodean realm where right and left meet, I have news for you. You will never convince a court that the government has no power to collect taxes. You will never convince anyone that you are a sovereign citizen not bound by the law. Regardless of your citizenship, if you are on a country's territory, you are bound by its laws. Everywhere on Earth. Even Antarctica, because every country with a presence in Antarctica has laws enabling it to prosecute crimes committed there. Go ahead. Post a YouTube video of you kicking a penguin and see how fast someone turns up at your door with a warrant.
There's a broad consensus about a lot of things in American society. We need paved roads and schools and some sort of plan so old people and the handicapped can survive. We need people to make sure foods are clean and airplanes don't collide and toxins don't get dumped in the rivers and radio stations don't try blasting each other off the air on the same frequency. Politics in America is played between the 30-yard lines. If you want to suit up and wait in the parking lot for someone to throw you a long pass, lotsa luck. There are a lot of dumb voters, but there are enough sensible ones to keep a lot of ideas where they belong - on the lunatic fringe.
I am never going to vote for the kind of candidate than many non-voters seem to want, and neither are any of the other voters I know, Democratic or Republican. So if you want a radical alternative to the candidates now running, you raise money, collect signatures and get them elected. It is not my job to fix your dissatisfaction with the system.