Americans are more divided along partisan lines than ever. They yearn, more than ever, for politicians who are willing to compromise to achieve results.

This is the paradox at the heart of modern politics.

According to a new report from the Pew Research Center, 71 percent of Republicans and 58 percent of Democrats say their parties have not done a good job of standing up for traditional positions.

Yet 80 percent of those surveyed say they favor “political leaders who are willing to make compromises in order to get the job done.”

What is a politician to do in the face of these seemingly irreconcilable urges?

A thoughtful new book by political philosophers Amy Gutmann and Dennis Thompson, “The Spirit of Compromise: Why Governing Demands It and Campaigning Undermines It,” offers a guide, if not a solution, to this puzzle.

Gutmann, president of the University of Pennsylvania, and Thompson, a professor of government at Harvard, refrain from either rosy paeans to compromise or partisan finger-pointing at particular culprits.

Not that they think blame is equally shared. In an interview, Gutmann made it clear that she endorses the assessment of Thomas Mann and Norman Ornstein, in “It’s Even Worse Than It Looks” that the Republican Party has become increasingly extreme in outlook and intransigent in behavior.

The Pew numbers buttress this assessment. They demonstrate a persistent and widening “compromise gap” between the parties.

In 1987, 66 percent of Republicans and 77 percent of Democrats said they favored political leaders willing to compromise. In 2012, nearly the same share of Republicans — 68 percent — took this view, while the proportion of pro-compromise Democrats had risen to 90 percent.

However, Gutmann said, casting blame in Republicans’ direction is distinctly unproductive. Rather, “if the problem, as almost everybody agrees, . . . is increased polarization, then the solution isn’t going to be blaming one of the parties.”

Instead, Gutmann and Thompson take a bird’s-eye view of compromise and what they call the “compromising mind-set” necessary for effective governing.

Note the emphasis on governing. Gutmann and Thompson argue that there is a necessary place — campaigns — for the uncompromising mind-set, in which partisans tenaciously stake out positions and discredit opponents.

“Here is the internal tension in political compromise,” they write. “The democratic process requires politicians both to resist compromise and to embrace it.”

The problem occurs when the prevalence of the permanent campaign transplants the uncompromising mind-set to the sphere of governing, like an “invasive species” growing out of control.

Gutmann and Thompson distinguish between achieving compromise and finding common ground. However desirable finding common ground may be, the parties’ stark ideological divide means that the possibility of achieving it becomes smaller the more important the issue involved.

This leaves the less satisfying mechanism of compromise, which requires both sides to bend on matters of principle and yields messy, internally contradictory results. Compromises are inherently imperfect.

Yet compromise is necessary because the “tantalizing dream” of a clarifying election that dislodges the gridlock is illusory, given the close divide and checks-and-balance structure of government. Meanwhile, as useful as presidential leadership may be, “no president can prevail as long as Congress remains recalcitrant.”

And the status quo, albeit for different reasons, is unacceptable to Democrats and Republicans alike. Sticking with things as they are sounds like the conservative ideal, except in a moment of expiring tax cuts and mounting debt. Moreover, compromise is not only for the moderately inclined; the authors cite staunch partisan compromisers such as Ted Kennedy and Alan Simpson.

How to create more such lawmakers? Gutmann and Thompson discuss various potential solutions: reforming the filibuster, lengthening congressional terms, limiting the need for nonstop fundraising, and adopting open primaries that could mitigate the extremeness of candidates now produced by party primaries.

Still, these changes are simultaneously elusive and admittedly inadequate to the monumental task of carving out space for the compromising mindset to take hold. Gutmann and Thompson conclude with an exhortation from the Beatles: “You tell me it’s the institution. Well, you know. You’d better free your mind instead.”

The House and Senate are full of people who are better than the institutional constraints in which they operate. They chafe against the divisive imperatives of the permanent campaign. They yearn for the chance to strike a deal. For these lawmakers, and for the voters who claim to value compromise, reading this book would be a good start.

It is silly to imagine that a new mindset can take hold overnight. But it is equally sad to conclude that the cause of compromise is entirely futile.

ruthmarcus@washpost.com