MANCHESTER, N.H. - Mitt Romney took the reins of the Republican Party here tonight, vowing to put an "end to the disappointments" of the Obama administration while making the pivot to the general election official, acknowledging the need to reintroduce himself to the coveted electorate.

"Tonight is the beginning of the end of the disappointments of the Obama years, and it's the start of a new and better chapter that we will write together," said Romney, who spoke just 30 miles from where he launched his bid for the White House last spring.

"After 43 primaries and caucuses, many long days and more than a few long nights, I can say with confidence - and gratitude - that you have given me a great honor and solemn responsibility," said Romney on an evening when he won primaries in New York, Pennsylvania, Connecticut, Rhode Island and Delaware. "And, together, we are going to win on Nov. 6."

Describing the primary race as an "extraordinary journey," Romney noted that many voters may be "just now beginning to focus on the choice before the country."

"In the days ahead, I'll look forward to spending time with many of you personally," he said. "I want to hear what's on your mind, hear about your concerns and learn about your families. I want to know what you think we can do to make this country better and what you expect from your next president."

"And I'll tell you a little bit about myself. I'll start out talking about my wonderful wife, Ann, of course," said Romney, whose wife had introduced him.

"I'll probably bore you with stories about my sons and my grandkids," said Romney, later joined by his eldest son, Tagg, and two of his grandsons.

Romney's speech, titled, "A Better America Starts Tonight," was the sign post of the campaign's shift the general election, a senior adviser to the candidate's campaign told reporters earlier today. The next phase of the campaign, the advisor said, "will be marked by more direct engagement with President Obama and his campaign."

Tonight, Romney did just that, characterizing the Obama years as a time during which "we have seen hopes and dreams diminished by false promises and weak leadership."

Posing a series of questions to the crowd of more than 500, such as, "Is it easier to make ends meet?" ("No!" the crowd screamed) and, "Do you have a better chance to get a better job?" ("No!" the crowd yelled again), Romney accused the president of being unable to run on his record.

"You know, if the answer were 'yes' to those questions, then President Obama would be running for re-election based on his record … and rightly so," said Romney. "But because he has failed, he will run a campaign of diversions, distractions and distortions. That kind of campaign may have worked at another place and in a different time. But not here and not now.

"It's still about the economy … and we're not stupid," he said.

Romney, drawing on the theme of fairness that President Obama has used in previous speeches, in particular during his State of the Union address earlier this year, declared, "This America is fundamentally fair."

"We will stop the unfairness of urban children being denied access to the good schools of their choice," said Romney. "We will stop the unfairness of politicians giving taxpayer money to their friends' businesses. We will stop the unfairness of requiring union workers to contribute to politicians not of their choosing. We will stop the unfairness of government workers getting better pay and benefits than the very taxpayers they serve. And we will stop the unfairness of one generation passing larger and larger debts on to the next.

"As I look around at the millions of Americans without work, the graduates who can't get a job, the soldiers who return home to an unemployment line, it breaks my heart," said Romney. "This does not have to be. It is the result of failed leadership and of faulty vision. We will restore the promise of America only if we restore the principles of freedom and opportunity that made America the greatest nation on earth."

The Obama campaign released a statement following Romney's speech in which it too appeared poised and ready for a general election showdown.

"The title for Gov. Romney's speech tonight should have been 'Back to the Future,' because he has proposed a return to the same policies that got us into the economic crisis in the first place - forcing the middle class to pay for tax cuts for millionaires and billionaires, letting Wall Street write its own rules and eliminating investments in the security of the middle class," said Ben LaBolt, Obama's campaign spokesman. "Despite all evidence to the contrary, Gov. Romney believes that showering the wealthiest Americans with special giveaways will make the middle class thrive.

"Mitt Romney has spent the past year out on the campaign trail tearing down the president with a negative message that even Republicans who have endorsed him have criticized," said LaBolt. "This marks the end of that monologue. Now he must put his record and his agenda next to the president's."