As Mitt Romney sees it, this week’s economic data ought to be bad news for President Obama. The economy slowed to a crawl in the second quarter and the current quarter looks like more of the same. A nascent housing recovery was offset by setbacks in manufacturing. A drop in military spending previewed the pain that is to come if lawmakers don’t find a way to avert even deeper automatic cuts that Republican lawmakers insisted on for 2013.

This is just what Mr. Romney’s campaign strategy was built on — a weak economy that would doom the president. Yet the stock market largely brushed off the grim reports, and opinion polls show Mr. Obama is ahead right now, including in voters’ assessments of the candidates’ ability to deal with economic issues.

The problem with Mr. Romney’s “blame Obama” mantra is that Mr. Obama is not responsible for the deep and protracted recession that predated his administration and is at the root of the persistently high unemployment. Job creation under Mr. Obama’s term far outpaced the job growth following the first recession of George W. Bush’s presidency in 2001. New evidence released this week showed recent employment has been stronger than previously tallied.

Mr. Obama is not free from responsibility for the economy. He did not push hard enough for a larger stimulus and more robust housing relief. He also changed focus prematurely from creating jobs through stimulus to reducing the deficit through spending cuts.