Well, the claim is that a bunch of jobs will be created with all the infrastructure spending due to companies having to hire them for the work. There are a few problems with the notion that this is going to save the economy, however:
1) Most of the infrastructure spending, at least on the things like bridges, roads, repairs, etc. will be performed by state and local depts. of transportation - meaning that it will be govt. workers who are already employed who will be doing these projects.
2) For the work that will be farmed out to private firms, most of these firms are already in slowdown as it is, so the extra work may help to keep them from laying off workers, but it won't stretch their capacities beyond what they can handle so that they'd need to hire new workers.
3) Does anyone really think that we have 3 million unemployed construction workers sitting around just waiting to be hired? No. Most of the people losing their jobs are in manufacturing, support services, etc. etc. and hence would be no more qualified, or even able, to take a construction job than 0bama himself is.
It's all a con that the Dems are hoping to play on the America people to get us to go along with their big-spending swagbag for Democrat contributors.
Growing up, I was always taught that the best way to get help is to help yourself. Apparently that is not the norm anymore. You have to rely on big daddy government now. Just look at New Orleans.