A litmus test in politics is like a test that helps you figure out what someone thinks about a certain topic. It's like asking your friend if they like strawberry ice cream or chocolate ice cream better to know what kind of ice cream to get for them.
But instead of ice cream, the topic could be something really important like whether someone believes in certain rights or not. For example, if you asked someone if they support equal rights for everyone, regardless of their skin color, religion, or gender, their answer might give you a good idea of what their beliefs are.
So, a litmus test is like a way to test someone's opinions on important political issues to see if they align with your own beliefs. It can help you decide if you want to support them or not, or if you want to vote for them in an election.