LAST WEEK marked the true opening of the 2012 general election campaign, with President Obama and all-but-certain Republican nominee Mitt Romney offering dueling speeches, visions of government and caricatures of the other side. The remarks — both candidates’ appearances before the American Society of News Editors plus Mr. Romney’s primary night victory speech — presented an instructive yet disappointing road map to the long months of campaigning ahead.

Instructively, each candidate outlined his vision of governing. Mr. Obama, while cautioning that he does not believe “government can or should try to solve every problem,” endorsed an active federal role to address what he termed “the defining issue of our time” — “Can we succeed as a country where a shrinking number of people do exceedingly well, while a growing number struggle to get by?” Mr. Romney denounced the president’s “government-centered” approach, arguing that “the vitality and dynamism of the American spirit . . . is being deadened by a series of government programs that have been increasingly invasive and have attacked economic freedom.”

Both candidates distorted the position of the opposing side. Mr. Romney had a point when he accused the president of resorting “to one of his favorite strategies, setting up a straw man to distract us from his record” — and then proceeded to do the same, falsely describing the president, for example, as “apologizing for America abroad.” Mr. Obama, meanwhile, presented the throw-Grandma-from-the-train version of the Republican budget, leaping from an assumption that its cuts would be evenly distributed to a dismal world in which children would go hungry and national parks would close.

Even more disappointing was the degree to which each ducked a central question that will confront the next president. Mr. Romney, like the rest of his party, blithely pretends that there is no need for higher tax revenue to deal with the burgeoning debt — indeed, he irresponsibly argues, tax rates can be lowered across the board. Mr. Romney complained that the president had criticized “policies no one is proposing,” yet the gauzy outlines of the House Republican budget that Mr. Romney has endorsed invite such supposition: if Republicans are unwilling to lay out the hard choices their cuts entail, they can hardly be surprised when the other side fills them in.

Mr. Obama minimized the danger of the debt, pooh-poohing arguments for “draconian cuts because our deficit is so large; this is an existential crisis, we have to think about future generations, so on and so on.” He said “that argument might have a shred of credibility were it not for their proposal to also spend $4.6 trillion over the next decade on lower tax rates.” Mr. Obama is correct about the irresponsibility of promising lower tax rates without specifying accompanying loophole-closing. Yet the argument that dramatic action is needed to forestall a debt crisis has far more than a “shred” of credibility. Particularly galling was the president’s reference to “the bipartisan Simpson-Bowles commission that I created” — and never mind how he left its recommendations to twist in the wind.

The country needs entitlement reform, and Mr. Obama’s first term has yielded disappointment in that regard. But the Republican solution represents such a lurch rightward, and leaves so much unsaid, that it cannot claim to offer a responsible alternative.