While it is true that the new roads, bridges, water treatment plants, etc. will be years down the road, the other part of the infrastructure plan will be seen immediately, tens of thousands of good paying, long term jobs. The immediate boost to local economies will leave the Repubs cleft on a forked stick - do I claim credit for something that I clearly opposed (just as they are doing now. And don't think his/her Democratic opponent will fail to point this out - loudly and often) or do I continue telling my constituents that it's all a big lie, that this will only lead to massive inflation and national economic ruin?
I think many of the voters that have supported the Rs will change their votes to Ds. Why? Because, in many ways what we have in this country is a similar situation to what existed in post-war America, an opportunity to modernize the country after the economic collapse of the Great Depression. If you look at the period 1946 - 1960 there was a boom in infrastructure building. This produced prosperity for the working and middle classes. They, in turn, rewarded the Democrats with control of the House and even in the Senate it was moderate, and even liberal, Republicans who were voted into office. Republicans who, at least in public, echoed the Democrats vis-a-vis infrastructure spending.