Updated

A year and a half after Congress passed the economic-stimulus plan, the state aid and tax cuts in the package have nearly ended, but some of the big infrastructure projects touted by the Obama administration are still months from visible development.

Critics of the stimulus have seized on the slow progress as evidence that the plan has been a costly failure. And amid a continued high jobless rate, that argument appears to be resonating with voters.

The administration said stimulus spending was always intended to roll out in stages, over a period of two years, and that the pace of outlays for infrastructure would be slower than for other parts of the package. But recent opinion polls suggested the White House has struggled to communicate that message, particularly after its emphasis on "shovel-ready" projects during the debate over the plan's passage in early 2009.

In a Wall Street Journal/NBC News poll in May, just 18% of respondents said the plan was already helping to improve the economy, and just 20% said they thought it would help in the future. Confidence appears to have slipped from July 2009, when 48% of respondents said the plan was helping the economy already or would help it in the future.

The administration said stimulus spending was always intended to roll out in stages, over a period of two years, and that the pace of outlays for infrastructure would be slower than for other parts of the package. But recent opinion polls suggested the White House has struggled to communicate that message, particularly after its emphasis on "shovel-ready" projects during the debate over the plan's passage in early 2009.

In a Wall Street Journal/NBC News poll in May, just 18% of respondents said the plan was already helping to improve the economy, and just 20% said they thought it would help in the future. Confidence appears to have slipped from July 2009, when 48% of respondents said the plan was helping the economy already or would help it in the future.

For more on this story from the Wall Street Journal click here