Winner of Michigan and Arizona primaries:

Romney’s slim win in Michigan and wider one in Arizona (where he was boosted by the state’s Mormon population) have therefore done little to dispel his party’s concerns that the candidate is failing to transform anti-Obama sentiment into excitement to take back the White House.

In an interview late Tuesday with The New York Times, former Alaska governor and vice presidential candidate Sarah Palin noted, “It does seem that his campaign is having a tough time sort of garnering…not just that support, but that energy that’s needed….just the fact that he’s had such a fight in his home state is evidence of that blessing not yet being given to him across the board.”

Obama, in the meantime, has sharpened the contrast between his own policy proposals, aimed at bolstering the middle class, and Romney’s image as a capitalist looking to protect the wealthiest Americans’ wallets.

Gradually improving jobs and market data have further helped the president make the case that he, and not Romney, is the best positioned to shepherd the US economy into a more robust phase of recovery.

Those figures have led analysts like The New Yorker’s John Cassidy to offer a withering appraisal of Republican presidential prospects, even in the wake of Romney’s latest primary successes. “It is virtually certain that the Republicans will be saddled with a battered candidate whose approval rating with independents has plummeted almost twenty percentage points over the past couple of months (Romney),” Cassidy wrote Wednesday, “or, less likely but still not completely out of the question, with a surefire loser (Santorum).”

New York Times columnist Maureen Dowd was even more scathing. “Mitt Romney needs to be left alone to limp across the finish line,” she wrote cheekily on Wednesday, “so he can devote his full time and attention to losing to President Obama.”