One was the supreme court ruling that said the obamacare "tax/penalty" was constitutional. Since the government can now impose a penalty for not buying a product, and it controls the amount of the penalty and the cost of the product, the citizens are screwed.
The only way out of this is to leave the country and renounce your citizenship. Hold on there. The State Department levies a "fee" of $2,350 to release you from your obligations as a citizen. It was recently increased from $450. The increase was justified by claiming that demand for the service had jumped. So if demand increases from a trickle to a flood what is to stop the government from increasing the fee to $10,000 or $100,000 or $1,000,000?
Unless both of these measure are not just capped but struck down completely the route to slavery is clear.
It goes back much farther than that, IMO. The 16th Amendment (...power to lay and collect taxes on incomes, from whatever source derived...) is naked slavery.
A 100% tax rate is by definition, involuntary servitude. All you earn by the fruits of your labor is seized. Therefore, any lesser percentage is merely a matter of degree.