A sock puppet has no interest in actually participating in a discussion. It's only interested in harping on one side of a political debate. You ask for specifics and they just repeat a bunch of talking points.
Someone like this might be a sock puppet, but they might also just be an ideologue. A sock puppet will have created a login, assuming a login is necessary, just for the purpose of sock puppetry. An ideologue will stick around and argue other topics.
Sock puppets also like to work in teams, you'll see them in groups of two or three 'me-too'ing each other's points. If this happens, all of them will have created accounts specifically for that purpose. Sometimes they'll also all have the same IP address. This kind of manipulation is easy to detect, so generally you'll only see them rarely and in the short window between their spamming and the subsequent detection and banning.
Someone like this might be a sock puppet, but they might also just be an ideologue. A sock puppet will have created a login, assuming a login is necessary, just for the purpose of sock puppetry. An ideologue will stick around and argue other topics.
Sock puppets also like to work in teams, you'll see them in groups of two or three 'me-too'ing each other's points. If this happens, all of them will have created accounts specifically for that purpose. Sometimes they'll also all have the same IP address. This kind of manipulation is easy to detect, so generally you'll only see them rarely and in the short window between their spamming and the subsequent detection and banning.