They are certainly more likely to challenge a president if they think he's weak, but that perception depends almost entirely on what the president does once in office, not on his popular vote. He had proven his toughness under fire by defeating those who challenged his authority, and his opponents from Washington to Tehran and Moscow knew they were in for a real fight if they came after him. Clinton's power dropped initially when his wife's national health-care scheme was shot down, and then grew when he boxed the Republicans' ears on the occasion of the government shut down. As usual, Machiavelli is the most reliable guide to the workings of political power, and he reminds us that a successful leader whatever his tactics and methods is always hailed and obeyed, while a failure is bemoaned and challenged. It's all about winning and losing, and new battles can quickly change the balance of power.
Political power comes and goes with astonishing speed.
Just ask Newt Gingrich, who was briefly one of the most powerful men in the world, only to be defenestrated by his own former followers. Or ask George Bush the Elder, whose approval ratings broke all records less than a year before his electoral defeat. Most of the talk about a feeble mandate comes from people who have never exercised real power, but love to theorize about it, or from big-time losers like Bob Dole. That's what political power is all about. He should also vigorously reject the silly calls for a bipartisan administration.