The tedious fable of the Republican primaries, "The Tortoise and the Hares," is limping toward its predictable close. But if "fear the turtle" turned out to be wise advice for Mitt Romney's Republican opponents, the general election promises an even bumpier road for the plodding candidate.

"We hit the reset button and the campaign begins anew with a different opponent," Romney's senior adviser, Eric Fehrnstrom, told reporters. "We'll be able to draw sharp contrasts with the president and the president alone, not worrying about our competition. It will be a different race at that point, and the numbers will begin again."

He wishes. Romney would be a general election opponent who needs to be taken seriously, which is why the Obama campaign has been doing that for so long. But Romney emerges from the primary marathon a more bruised, less adept candidate than expected.

And much as the Romney campaign might wish otherwise, candidates are not iPods, capable of being easily restored to factory settings. Voters may not be fully engaged; their memories may be fleeting. Yet the lingering negative impressions remain of an uninspiring candidate in an uninspiring primary season.

Consider the verdict of Republican pollster Bill McInturff in the wake of the latest poll that he and Democrat Peter Hart conducted for NBC and the Wall Street Journal: "The word you'd have to use at this stage is 'corrosive,' " McInturff said.

The campaign has not been kind to Romney's image. Nearly four in 10 voters said they had a somewhat or very negative view of Romney, compared to one in four a year earlier.

Meanwhile, voters are both more enthusiastic about President Obama and more optimistic about the economy. Last August, voters were almost evenly divided between Obama and Romney; now, Obama leads, 50 to 44. The president's support among white working-class voters edged up to 43 percent from the dangerous, south of 40 percent levels of previous months. Nearly six in 10 believe that the worst of the recession "is behind us," up from half in November.

The optimistic scenario for Romney is that the toxic legacy of the primary season will prove to be as fleeting as it was for Democrats in 2008.

But there are two big differences between Clinton-Obama 2008 and Romney-Santorum-Paul-Gingrich 2012. First, whatever hard feelings remained between the candidates' supporters after Hillary Clinton eventually conceded, Obama enjoyed an energized following. In this campaign, the words "enthusiasm" and "Romney" do not appear together in the same sentence without the being accompanied by the phrase "lack of."

More important, the Republican primary -- unlike the Democratic contest in 2008 -- has pushed the all-but-certain nominee further to the ideological edge. Romney will survive Rick Santorum, but he will suffer a Santorum hangover.

During the course of the campaign, Romney has ramped up his rhetoric on issue after issue, from immigration to taxes to contraception, in ways that threaten to undermine his chances in the general election. Instead of positioning himself to exploit Obama's weakness among white, working-class voters, Romney has railed against union bosses, denounced the auto bailout, and made himself the candidate of Bain Capital, spouting unfortunate Richie Rich-isms.

Romney could yet win. But as much as his campaign would like, there is no magic button.