Does anyone remember the American Jobs Act? A year ago President Obama proposed boosting the economy with a combination of tax cuts and spending increases, aimed in particular at sustaining state and local government employment. Independent analysts reacted favorably. For example, the consulting firm Macroeconomic Advisers estimated that the act would add 1.3 million jobs by the end of 2012.

There were good reasons for these positive assessments. Although you’d never know it from political debate, worldwide experience since the financial crisis struck in 2008 has overwhelmingly confirmed the proposition that fiscal policy “works,” that temporary increases in spending boost employment in a depressed economy (and that spending cuts increase unemployment). The Jobs Act would have been just what the doctor ordered.

But the bill went nowhere, of course, blocked by Republicans in Congress. And now, having prevented Mr. Obama from implementing any of his policies, those same Republicans are pointing to disappointing job numbers and declaring that the president’s policies have failed.

Think of it as a two-part strategy. First, obstruct any and all efforts to strengthen the economy, then exploit the economy’s weakness for political gain. If this strategy sounds cynical, that’s because it is. Yet it’s the G.O.P.’s best chance for victory in November.