[WatchDog]

Building up karma only requires that on balance one's contributions are popular.

Many accounts will contribute constructively on topics that are technical or objective, but then become more antagonistic on controversial or political topics.

So long as they don't severely break site rules, it's unlikely that they will be subject to major moderator action.

[MichaelZuo]

Hmmm… This would imply the value of karma is much less and my threshold should be much higher?

To keep the bar at roughly the same relative difficulty.

Say 10,000+ karma?

If so, my example would no longer apply.

[Karrot_Kream]

This site has gotten a lot more popular and so it's a lot easier to rise up in karma these days. It's really easy to get lots of upvotes and downvotes in pretty much any of the controversial/political threads on the site because they get a lot of attention, a lot more than the more technical or sedate posts. My guess is the mods don't have the time to look at as many of the comments anymore just because there are so many.