WASHINGTON — President Obama on Monday called for a $50-billion surge in spending on the nation’s roads, runways and railroads, his latest effort to respond to the stubbornly sluggish economy in a political climate turning against his party.

Speaking at a union-organized rally in Milwaukee, the president said his proposal would put construction workers back to work and rebuild deteriorating infrastructure.

‘It’s a plan that says, even in the aftermath of the worst recession in our lifetimes, America can still shape our own destiny, we can still move this country forward, we can still leave our children something better – something that lasts,’ the president said, in a campaign-style speech that sought to make the case for his economic policies.

The Labor Day speech came as Democratic candidates were launching the final leg of their campaigns and, in many cases, facing a harsh assessment from voters frustrated by the pace of economic recovery. Polls show voters feel uneasy about the economy, unhappy with the rising deficits and willing to give Republican policies a try.

The White House will use this week to show it is reacting to that climate. The infrastructure plan was slated to be the first in a series of proposals […]