You're not radically less likely to come in contact with people of other political views, you are just more likely to be surrounded by people who keep their political views quiet, because they know what's good for them.
Most of the US is purple, the difference is whether it's a blue-ish purple or a red-dish purple.
You are much less likely to come in contact with people of other political views than in times past, and there is plenty of detailed research to back this up. One recent example:
Most of the US is purple, the difference is whether it's a blue-ish purple or a red-dish purple.