I hope you're being ironic. This started in 1984 when President Reagan signed the bill that was overwhelmingly supported by both parties. So, for 40 years, SS income has been taxed. Since earned income is subject to SS tax and you don't receive a deduction, it amounts to double taxation when benefits are received.
That system is badly in need of a total revamp: limits on income that is taxed is dumb, 3 and 4 individuals drawing from a single taxpayer's SS benefit is stupid, COLA increases ad infinitum means, if you live long enough, you'll take 3X+ more money out of the system than you ever put in (not counting your spouse, your divorced spouse, a minor on disability, etc.). The world's greatest Ponzi scheme: every dollar collected is paid out in benefits currently (and then some) - pretty much the definition of a Ponzi scheme, right? I'd be all for privatization of SS but no one in Congress will ever go for it, imo.