Megan McArdle says the individual mandate — the “tax” which underpins the law — is politically vulnerable:

To see why, consider a fictional middle-class family. Call them the Petersons. Mom, Dad, two swell kids. Dad has his own landscaping business, and Mom works part time as a massage therapist. Together, they pulled in $90,000 in family income in 2013, and that’s about what they expect to get in 2014, so that’s what they put into the system when they go to buy health insurance. They’re pleasantly surprised to find that they can get a Silver plan for $688 a month. That’s a lot of money, to be sure, but it comes with a substantial subsidy and they’re happy to get it.

Over the year, Mom picks up another regular massage client, and Dad gets a few more landscaping jobs than he had last year, and at the end of the year, good news: Their family income is now $95,000! The recession is over for this family.

Or is it just beginning? When their family income passed $94,000, the Petersons moved from just under 400 percent of the federal poverty line to just over. Which means that they no longer qualify for subsidies on their health insurance, and the Internal Revenue Service would like that $8,500 back, please.

I’ve written before that ObamaCare’s un-phased subsidies put an effective cap on middle class income, a point from which families simply can’t afford any additional income. Stay put, comrades — you’ve gone as far we feel you should.

That’s no accident. That’s wealthy Democrats closing the door behind them. This law, this “benefit,” might be the most sinister tool ever concocted for protecting the haves from competition from the have-nots.