If you ask me, the single most consequential political act of my lifetime is likely to be President Obama's decision to throw the Bowles-Simpson recommendations under the bus. That may have destroyed the last chance to prevent a budget train wreck. Yet Rauch believes that Obama is one of the good guys, a professional able to compromise.
I think he has a contender. And obviously the context Arnold must have in mind is a political act in this country and how it affects this country. Otherwise, the fall of the Berlin Wall and the consequent end of the Soviet Union on Christmas day of 1991 have to count above Arnold's choice.
So sticking with that context, let me give my contender that I think is more important than his: George H.W. Bush's decision to make war on his erstwhile ally Saddam Hussein. While that war looked cheap to America at the time (only about 150 U.S. lives lost and a large percent of the budgetary cost paid by some Arab nations and Japan), one unintended consequence was the 9/11 attacks. Those, in turn, led to a dramatic increase in financial regulation, a dramatic drop in civil liberties, and a dramatic drop in the freedom to travel.
So, dear readers, what say you? What are your contenders? Keep in mind that I don't want it for your lifetime but for Arnold's. I was born in 1950, he in 1954. So how about the most consequential political act in 1955 or later.
As co-blogger Bryan says, please show your work, that is, give your reason(s).