If unemployment were at 6 percent instead of 9.6 percent, the car metaphor would seem positively Lincolnian. Unfavorable events can make any communicator look bad.

But Obama’s problem is deeper than his economic challenges. His policies as president — particularly the creation of a health entitlement and his Rooseveltian emphasis on federal spending to create public-sector jobs — have reopened and widened the main partisan division in American political life. Every public issue has become a harsh, entirely predictable debate about the size and role of government. Obama’s initiatives, it turns out, could only be considered moderate on the skewed ideological scale of the Democratic Party. They are not only unpopular; they have made it impossible for him to maintain the pretense of being a unifying, healing, once-in-a-generation leader. It is the agenda that undermined the idiom.

With that image stripped away, Americans found Obama to be a somber, thoughtful, touchy, professorial, conventionally liberal political figure. Some like the demythologized Obama; others do not. But this profile would not be exceptional or remarkable in any town boasting a university faculty lounge. And it does not make Obama a particularly compelling party leader in a difficult midterm election. One of the best communicators I also ever saw in a campaign became an ineffective messenger as president — precisely because the appeal that made him a phenomenon is no longer credible.