Taking Social Security early is is not an irreversible decision. Through a little-known (but ever more popular) legal loophole, you may decide, upon full retirement age, to "un-do" your previous choice to take Social Security early. To do so, you must fill out some forms and provide a check for the entire amount of Social Security received. Importantly, you do not need to repay the interest you could have earned over that time.
In essence, as the 401K Planning blog points out, you can work this so that you are receiving an interest-free loan from the government.
Is this a strategy you can afford to try-out? Is this a strategy the government can afford to offer? I welcome your opinions!