Obama congratulates Romney

In a rare moment of comity, President Obama called Mitt Romney on Wednesday to congratulate him on securing the Republican presidential nomination even as his campaign was launching a new line of attack against Mr. Romney’s record as governor of Massachusetts.

Although the already intense campaign is expected to grow increasingly negative as November draws closer, the White House said Mr. Obama and Mr. Romney had a “very good conversation” Wednesday and wished each other’s families well during the upcoming race.

“President Obama said he looked forward to an important and healthy debate about America’s future and wished Governor Romney and his family well throughout the upcoming campaign,” the Obama campaign said in a statement.

Mr. Romney wrapped up his party’s nod Tuesday night after the Texas Republican primary pushed him over the 1,144-delegate threshold needed to win the nomination. All of Mr. Romney’s main rivals had dropped out of the race over the past few months.

Despite the cordial nature of the call, there was no cease-fire for the two men’s campaigns. Team Obama shifted from attacking Mr. Romney for his tenure at Bain Capital to his record on job creation in Massachusetts, which it called “among the worst in the nation.”

Meanwhile, Mr. Romney continued to hammer Mr. Obama over stimulus projects and federal investment in green energy companies such as Solyndra, a solar firm that received a $535 million government loan in 2009 only to go belly up two years later.

The jabs from the two sides come as polls show the race tightening and Mr. Romney looks to use the summer months and his new status as the presumptive Republican nominee to shore up his standing with the party’s base voters, many of whom have yet to wholeheartedly embrace his candidacy.

Polls give Mr. Romney the upper hand when it comes to improving the still-struggling economy, the most critical issue for voters. But Mr. Obama has a far deeper war chest to spend on the election and scores higher in polling on his likability and on excitement about his candidacy from his most dedicated supporters, although their enthusiasm has dipped significantly from 2008 levels.

Mr. Obama’s campaign has mentioned Mr. Romney’s record in Massachusetts as a vulnerability in the past, but Wednesday it honed in with the campaign’s senior strategist David Axelrod sending out a five-page memo titled “Romney Economics: It Didn’t Work Then And It Won’t Work Now.”

In it, Mr. Axelrod accuses Mr. Romney of failing to deliver on his gubernatorial campaign promise to use his business acumen to help create jobs for the state despite a nationwide economic expansion during his time in office from 2003 to 2007.

“Romney campaigned for Governor on the promises of more jobs, decreased debt and smaller government,” Mr. Axelrod wrote. “When he left office, however, state debt had increased, the size of government had grown, and over his four years, Massachusetts’ record of job creation was among the worst in the nation.”

Even though Republicans have criticized the president over Solyndra throughout the crowded Republican primary, Mr. Romney this week used the failed federal loan to push back on Mr. Obama’s onslaught of negative ads about his time at Bain Capital and the manufacturing plants and businesses that were closed after Bain took control of them.

Republicans have compared Mr. Romney’s record at Bain to Mr. Obama’s explanation of his failed clean-energy spending, a parallel the White House had difficulty explaining away earlier this week.

“[The] difference in that, or overall view of what … huh, your responsibilities are as president and what your view of the economic future is,” Mr. Carney said during Tuesday’s briefing.

The Obama campaign tried to clarify the argument Wednesday, taking aim at Mr. Romney’s profits when companies were closed and people lost their jobs.

“There were winners and losers. But Mitt Romney always won,” Obama spokeswoman Stephanie Cutter said on MSNBC. “The way he’s talking about it is just wrong. It doesn’t qualify him to be president.”