Your reading comprehension skills are very poor, @topicOfTheDay.
'Abducted by aliens' seems to mean a Tory is inhuman. No, in context it clearly meant that the person's child is very left wing and so they are jokingly pointing out that their child is highly unlikely to join the YCs.
'I'd have thought I raised them to be better people' means that Tories are worse people than other voters. Fair. But still not bigoted: it means that in the poster's opinion, Tory policies are inconsistent with the moral code that they had hoped they'd instilled in their child. But it does not contain the 'hatred and intolerance' of other people that is required for bigotry. Disagreeing with you is not bigotry.
'Like I had failed' - anyone who is a Tory is a failure. No, again, you're confusing what the poster means here. They are not saying that Tories are failures. They are saying that they personally would feel like a failure if their child did not follow their political beliefs.
These are not unsubstantiated views - they are emotional responses to the question that was posed to us.
I think if you (wilfully?) misunderstood what your young charges were saying to you in the same manner that you've misinterpreted clear posts here, you'd have bigger problems with them than an unfortunate choice in political hero.