In other words, for the last few years private construction activity has been far below its historic norms. And so long as the private sector isn’t building houses and office buildings and factories, the government can build without crowding out private investment. But that window might not last much longer; at the current pace, private investment will be back to its historical average in another few years. It’s not now or never, exactly, but it very likely will be cheaper now to spruce up the nation’s transportation and energy infrastructure than it will be in the not-too-distant future.

I think Congress can be convinced. They just want the spending blame to reside with Obama.

and want to reap the benefits in re-elections too.  

Well, right. They want none of the blame and any of the potential credit.

We've had so much dysfunction in Congress that it's hard to remember what a competent legislative branch looks like.