Four years ago, Barack Obama campaigned as a transformational leader, promising a postpartisan presidency that would heal the wounds of the Bush era.

The great expectations many Americans had for the newly elected President Obama in November 2008 arose from his inspiring oratory, his compelling personal story and their own longing for change. Hopes seldom have been higher.

This Editorial Board took a realistic view in its 2008 endorsement of the president , calling both Obama and Republican Sen. John McCain "flawed" candidates. "Ideally Obama would have more experience and a long list of bipartisan accomplishments," we wrote at the time.

But McCain, whom this page had long admired for his personal heroism and bipartisan lawmaking, too often pandered to the far right of the GOP during an erratic campaign.

Similarly, this year, Republican standard-bearer Mitt Romney spent months and millions renouncing the relatively moderate record he compiled as governor of Massachusetts. Despite his move toward the center since winning the nomination, Romney's chameleon tendencies -- coupled with an economic plan that lacks credibility -- have left us with too many doubts about how he would lead the nation.

Those doubts, combined with our fundamental disagreement with even the postconvention Romney's positions on key issues, lead us to endorse Barack Obama for a second term as president despite our disappointment over the lost opportunities of his first four years.

By no means has Obama's first term been a failure. The stimulus package was an imperfect but necessary response to the economic crisis he inherited. The auto industry bailout saved tens of thousands of jobs. Today the economy is growing modestly, and unemployment is falling.

The president's signature achievement, the poorly understood Affordable Care Act , requires individuals to take responsibility for their health care costs by buying insurance or facing a tax penalty. No longer will governments and Americans with private insurance pick up the full tab for uncompensated care provided to the uninsured.

Obamacare will make coverage more affordable for millions. Protections for adults with preexisting conditions will take effect in 2014, as will state health care exchanges to enhance competition and transparency for those who buy on the individual market. Payment reform measures are designed to rein in costs by rewarding providers for results, not procedures. The law needs to be fully implemented -- not repealed, as Romney has pledged.

Obama deserves his best marks in foreign policy. Helped by his astute choice of Secretary of State Hillary Clinton, the administration's balanced, cooperative approach has repaired the country's image with its allies. The president ended the war in Iraq and started winding down the one in Afghanistan. He targeted Al-Qaida's leadership, above all bringing justice to Osama bin Laden .

Romney's postconvention shift from the neoconservative right to near the center on foreign policy, most notably during last week's debate, only validates the administration's economic sanctions against Iran and its prudent decision not to deploy troops in Syria.

The moderate Romney who reemerged after the convention is more congenial than the Tea Party fellow traveler who won nomination. But who can be certain which Romney will appear next? How can any American be sure where he stands on gay rights, immigration, climate change, reproductive rights and investment in education?

Romney's promise to lead the charge to repeal the Affordable Care Act is inconsistent with his work as governor of Massachusetts. More troubling, he's failed to articulate a viable alternative to Obamacare. And, as on so many issues, as Election Day nears Romney has tempered his criticism, suggesting that insuring every child in Massachusetts wasn't such a bad idea after all.

Whoever wins on Nov. 6, the most pressing immediate challenge will be reforming America's fiscal policy, beginning with avoiding the fiscal cliff of expiring tax cuts and reckless spending reductions triggered by the failure to reach a long-term debt reduction deal last year.

The biggest breakdown in Obama's first term was his inability to lead the nation toward reasonable solutions to the growing debt problem. It was a profound failure of leadership that has understandably left some 2008 supporters skeptical about his ability to make meaningful progress on the country's top domestic priority in a second term.

You would think that Romney, with his business smarts, would offer a coherent vision for the nation's budget challenges. Instead, he's conjured a magical economic plan with deep tax cuts and increased military spending. Romney would eliminate tax deductions to offset lost revenue, but he refuses to provide details . It's simply not credible.

The responsible long-range plan outlined by deficit hawks Alan Simpson and Erskine Bowles in their 2010 debt reduction report received too little air time during the campaign, no doubt because neither candidate would risk the political fallout from asking Americans to embrace a new era of shared sacrifice.

It's our hope that Obama, in the traditional sweet spot of the first year of a second (and final) term, would be more effective in finally forging a grand bargain with Republicans on long-term spending reductions, modest tax increases and strategic tax reform. If Romney were to win, his reelection campaign -- like the campaign to oust him -- would begin next Jan. 21.

Simpson and Bowles told the Star Tribune Editorial Board last month that a growing bipartisan contingent in Congress is committed to a genuine budget deal. And last week the president told the Des Moines Register that he would make the grand bargain one of his two priorities for 2013, along with immigration reform. We'll hold him to that pledge.

Obama has been too content to blame a recalcitrant Congress for lack of progress on fiscal issues. Other presidents -- Johnson, Reagan and Clinton come to mind -- have faced difficult legislative challenges and produced results by more effectively using the power of the office.

This president's legacy may well be defined by how well he leads the nation in taking the painful steps necessary to reduce its debt. He can still fulfill the expectations that greeted his first term if he meets the challenge of rallying the nation to build a more solid financial foundation for future generations.