First off, "I wasn't going to complain about Tanner until I got in trouble" is just the worst kind of whining. Taking other people down with you is not cool.
Second, if you look at things from an objective point of view (instead of the "Why did I get banned?" point of view), then you'll see that there are plenty of conservative posters who have been allowed to use alias accounts. Just ask jon_mx and HellToupee. (Jon will probably respond with "But what about all the hypocrite liberal aliases?!", and HT will probably say "New Hampshire is lousy with alias fraud" before deleting his post. Ba-dum-dum.)
Anyway, you're probably never going to get an official explanation that satisfies you. But based on what I've seen over the past 15 years, aliases have been unofficially allowed to exist as long as they behave themselves. But if you troll or break the rules, you're going to get popped. So, I would humbly suggest that the reason your own alias got clipped is because you were engaging in the same behavior that got your original account in trouble in the first place.
Now, it looks like the endless complaints about Tanner will result in a big win for the MAGA crowd. Tanner and his aliases may get permabanned. But the endless supply of Trumper troll aliases will be allowed to pollute the board -- not because the mods have a deliberate double-standard, but because the mods simply won't be able to figure out if accounts like @Bishop (a brand new account that just happened to make its debut in the P(S)F) are aliases or not. So they are forced to give them the benefit of the doubt.
This board is at its best when nobody whines and non-offending aliases are allowed to exist. When those two benchmarks are removed, then this place will become worse than the Geek Club at FFT.