Is the Affordable Care Act (popularly known as Obamacare) going to be responsible for the largest tax increase in US history? Republicans are now making this claim.
As it turns out, someone has done the math and out of a number of increases since 1950 or so, it rates as number 10. It comes in behind the Reagan tax increase of 1982, the Bush tax increase of 1990, and the Clinton tax increase of 1993. Details here:
http://www.motherjones.com/kevin-drum/2012/07/no-obamacare-not-biggest-tax-increase-historyRepublicans, you may consider spot 10 on that list to be serious enough, but lying about the numbers will make you look stupid.