The refrain of liberal timidity has continued to reverberate through the past decade. When Democrats lost control of the Senate in the 2002 elections, Clinton observed that in moments “when people are insecure, they’d rather have somebody who is strong and wrong than someone who’s weak and right.”

“The party of timidity” and of “drift … and capitulation” is how former presidential candidate Gary Hart characterized Democrats in “The Courage of Our Convictions: A Manifesto for Democrats.” When Swift Boat Veterans for Truth sought to discredit John Kerry’s war record, Democrats groaned that Kerry’s refusal to respond aggressively was a distressingly timid reaction.

In 2008, Obama’s critics questioned whether he had the backbone to defeat Hillary Clinton and John McCain; Obama repeatedly demonstrated his mettle and toughness. Now, as his critics reprise a version of this critique in 2009, Obama is championing the ambitious goal of achieving universal health care, while his broader agenda is as transformative as the sweep of the ideas advanced by either Ronald Reagan or George W. Bush — ranging from cap and trade to an education overhaul and a fresh set of financial regulations aimed at reining in Wall Street.