How do I stop the political text messages and others I don’t want?

I totally understand what you are talking about! They have truly been a problem for me, too. Here is what you can do:

• Block the message sender
• Then go back to the message and Delete & Report Junk

Unfortunately, these spammers keep using different phone numbers so if one is blocked, they just move on to another number. But by Deleting & Reporting Junk, Apple will start recognizing junk as … well, junk. The spammers make this a difficult task.

One more thing you can do. This link explains how to filter messages from unknown senders. You can still view those messages in case some are from valid numbers. But at least you will not receive the constant notifications. I use all three tips.

One last thought - contact your cellular carrier and ask if they have any way to try to control spam messages.