When Clinton came to power in 1993, he had wide majorities in both houses: 57 Democrats in the Senate, and 258 Democrats in the House. But the resistance to his key economic package was so intense within his own party that his plan passed by just a single vote in both the House and the Senate, and only after important elements of that plan—like a gasoline tax—were thrown over the side to win the votes of suburban Democrats.

When Obama was inaugurated in 2009, Democrats and their independent allies held 59 seats in the Senate, and when Al Franken finally claimed his seat months later, they had a supermajority of 60—enough to overcome a filibuster. But in order to hold those votes, the Obama Administration had to keep the cost of its Great Recession stimulus package under $1 trillion—an amount, his team later conceded, was too small to trigger a robust recovery. Similarly, in order to get reluctant Democrats like Joe Lieberman to vote for the Affordable Care Act, the White House had to kill the public health-insurance option, which left progressive Democrats disheartened. (As Obama accounts in his memoir, “A Promised Land,” the handwringing from members of his own party took much of the shine off his signature achievement as president, the biggest expansion of health care since Medicare.)

The two ex-presidents also share a common, painful experience with the political consequences of their battles. Clinton’s tax and budget initiatives were aimed at reducing the then-unacceptable budget deficit of some $250 billion—a deficit that helped propel independent candidate Ross Perot to 19 percent of the vote in 1992.