American politics have been dominated by a single party before. We're still here, and we're still free. Democracy still exists. The minority still has a voice. Now, one party is indeed gaining in prominence, but that is no cause for alarm. This isn't the end of disagreement between the common people, and as long as the people stay at odds on their views and ideologies and have the rights to express those opinions, the system in America will continue: there will be different parties. It's just that one might not be as powerful as the other, or might not be able to stop the other side from passing their own agenda, but the right to dissent is still preserved, and that minority can still become a majority. As long as we hold true to the Constitution, the odds of a one-party system becoming reality are incredibly slim.