Perhaps the only benefit of having a marathon-length 2008 presidential campaign is that the grueling ordeal may tell us what the candidates are really made of — particularly the newcomer, Sen. Barack Obama (D-Ill.)

[IMGCAP(1)]There are reasons to think that he’s the real deal — a “post-partisan” reformer who can free politics from the zero-sum ideological rancor of the current generation and develop bipartisan solutions and coalitions that really solve America’s problems.

His speeches and his book, “The Audacity of Hope: Thoughts on Reclaiming the American Dream” — self-written, not ghosted — exhibit a new sensibility. And, some of his proposals show originality and the possibility of attracting support across party lines.

In the book, he tends to blame the current climate of toxicity more on Republican “absolutism” than on Democratic “reaction,” but warns that “any attempt by Democrats to pursue a more sharply partisan and ideological strategy misapprehends the moment we’re in.

“I am convinced that whenever we exaggerate or demonize, oversimplify or overstate our case, we lose. … It’s precisely the pursuit of ideological purity, the rigid orthodoxy and the sheer predictability of our current political debate that keeps us from finding new ways to meet the challenges we face as a country.”

Amen to that. Rather than an “either/or” thinker, Obama shows at least a willingness to see matters empathetically from his adversaries’ point of view. He’s a “but/still/however/of course/on the other hand” thinker. That shows openness and the promise of change.

So the question then becomes, does he deliver? Is he willing to take on the ideologues and reactionaries in his own party and develop ideas that can attract Republican support? The answer, to this point, is “sometimes yes, sometimes no.”

In the “yes” category are his proposals — despite past strong support from teachers unions — for pay-for-performance experiments in education as well as for higher pay.

In a speech at the liberal Center for American Progress in October 2005, he said that “good schools will require both the structural reform and the resources necessary to prepare our kids for the future.”

He has proposed to fund “innovation districts” that, among other things, would “work with their unions to uncover bureaucratic obstacles that leave poor kids without good teachers, including hiring, funding and transfer policies.”

That’s not a national or frontal assault on one of the key problems facing American education — the inability of superintendents and principals to hire and reward good teachers and fire bad ones — but it’s a beginning.

He also showed courage in his speech at the March 4 anniversary of the 1965 civil rights march in Selma, Ala. — at a time when his credentials as a “real” African-American were being questioned — by delivering a Bill Cosby-esque message about cultural responsibility in the black community.

“Even as I fight on behalf of more education funding, more equity,” he said, parents need to “turn off the television set when the child comes home from school and make sure they do homework.”

He also said that blacks couldn’t progress “if we don’t start instilling in our young children that there is nothing to be ashamed about in educational achievement. I don’t know who told them that reading and writing and conjugating your verbs was something ‘white.’”

Along with Republican Sens. Norm Coleman (Minn.), Gordon Smith (Ore.) and Arlen Specter (Pa.), Obama has sponsored a bill to tighten auto emission standards on a gradual basis while granting flexibility to the auto industry.

And, he’s sponsored a “health for hybrids” bill that would grant auto companies relief from some of their health care burdens in exchange for investment of half the savings in fuel-efficient technologies.

As one of his staff members told me, Obama is “very undogmatic. His general approach is, ‘I am a progressive about ends, but I am a market guy. I am very open to different means.’”

On the negative side, however, Obama declined to join the bipartisan “Gang of 14” coalition to prevent Democratic filibusters of President Bush’s judicial nominations and block a GOP effort to alter Senate rules limiting the right to filibuster.

In his book, Obama says that while he understands and even sympathizes with some of the views of judicial conservatives, he couldn’t bring himself to help Bush’s nominees take the appellate bench.

As conservative critics have noted, even though Obama shows respect for Republicans and conservatives, he almost always comes down on the liberal side, producing National Journal and Congressional Quarterly ratings at the left end of the Democratic Caucus.

On foreign policy, Obama has proposed beginning U.S. troop withdrawals from Iraq starting in May — regardless of some evidence of recent military progress in Baghdad — but also says he favors leaving “a limited number of troops” to prevent Iraq from “becoming a haven for international terrorism and reduce the risk of all-out chaos.”

It’s hard to see how a limited number of troops could do what 140,000 troops can’t —especially after the U.S. has pulled out in the face of difficulty.

This long campaign will present Obama with chances to answer whether he can come up with large programs that might achieve consensus and success — for instance, a universal health plan that includes market incentives to keep down costs.

The nation also needs a long-term fiscal fix that involves both higher revenues (which fellow Democrats favor) and reductions in the growth of promised benefits (which they don’t), plus measures to increase Americans’ personal savings.

The record so far shows signs that Obama can be a tough campaigner. He got to the Illinois Senate by boldly challenging signatures on the candidacy petitions of a powerful incumbent. Yet in keeping with his promises of comity, he has declined to engage in ferocious public fights with his Democratic rivals, especially Sen. Hillary Rodham Clinton (N.Y.).

Finally, there remains the question of inexperience with national and international affairs. A businessman from Chicago told me recently, “Obama’s a fine young man, but the presidency is not an entry-level job.” Over the next year, we should find out whether this 46-year-old freshman Senator is up to the job.