I will not pretend to be unbiased towards opinions from the right. It's just that it gets tiresome to see topics which are not particularly political such as the first one (tech giants don't create jobs) get subverted over and over again into a political discussion (This is about the first link. In this case, I have read enough posts from this person to say that he is a right wing poster.). So I think a down moderation is the most appropriate action here, because I don't care to waste time reading another sterile political debate created by someone that seems to spend all day on /. preaching his political views.
About the third post I looked at, which is about digitizing records (This is the one where I accused the poster of talking out of his ass). I agree that this is a more political discussion, and that it is often more appropriate to make a reply than to moderate down. In this particular case though, the poster speculates about the execution of the digitization, and his post reeks of indignation and sarcasm. How can I expect an interesting discussion when the post starts on dishonest premises (because, remember, the digitization hasn't started yet, so why say that it's going to cost trillions?)? The answer is, I can't expect an honest discussion, because the poster's opinion is already set, and chances are that someone else will come up to present a similar viewpoint, but in a more reasonable and eloquent manner. So I think it's fair to moderate him down, and to have the discussion which the poster wants to make with someone who actually makes a few arguments in the favor of his viewpoint rather than to write a dumb act of faith.
TLDR: Yes, I am biased, yes, it is often better to write a reply than to mod down someone, but in this particular case, the poster gives no argument in favor of his view so I'd rather mod him down and read someone else with the same view who actually makes a case to argue against.