In the months leading up to the passage of the Affordable Care Act (known colloquially as Obamacare), President Obama and the Democrats insisted on numerous occasions that the individual mandate was absolutely not a tax. Instead, they argued that the power to impose the mandate was enumerated to Congress under the Commerce Clause of the Constitution.
Today, the Supreme Court ruled that the individual mandate is not constitutional under the Commerce Clause, but can be considered constitutional on the basis that it is by definition a tax.
Assuming that you consider the passage of the ACA to be in your best interest, are you comfortable with having been lied to for your own benefit? Is lying justifiable when it's in the service of a greater good?