In October, he predicted Clinton would be elected president two years from now, saying, "I will bet money on it, and I don't do that easily." He's said nobody is "better qualified" to be in the White House after President Barack Obama's second term ends.
At first glance, it may appear surprising to see Buffett contributing to a super PAC after repeatedly criticizing them for allowing people who can donate millions of dollars to have too much influence on elections. In 2012, he told Berkshire Hathaway shareholders he wouldn't contribute to any of the PACs accepting unlimited donations in support of Obama's re-election campaign.
"I don't want to see democracy go in that direction," he said. "You have to take a stand some place."
While it may appear Buffett has abandoned that stand, his contribution is not as big a departure from those principles as it first appears.
The PAC, Ready for Hillary, has a self-imposed contribution limit of $25,000 per individual, which is the amount Buffett donated.
A spokesman said the group "wanted to focus on grass roots" and give low-dollar donors a voice on a "big platform."
If Buffett had really wanted to back Clinton by joining the big-contributors club, he presumably could have given millions to a liberal PAC that doesn't limit donations, like Priorities USA Action.
A Berkshire spokeswoman confirmed that Buffett had donated $25,000 but wouldn't comment further.