Emergency measures always run the risk of being Trojan horses for longer-term agendas, because the scale and urgency make opposition that much harder. See how the GOP used the Department of Homeland Security re-org for unionbusting, or how the Bush admin argued that the Iraq war authorization also applied to domestic spying.
I think this bill is fairly good about that, though. That's mostly my judgment from reading the summary, but partly because some
Democrats are complaining that it doesn't achieve long-term goals like a new rail infrastructure.
The fact is there's some overlap in what makes for good fiscal stimulus and what makes liberals feel warm and fuzzy inside.
Food stamps and Medicare funds are easy to disburse quickly, are immediately spent back into the economy, and go towards things with real value. Putting aside the evil redistributionist part, it makes them more effective than tax rebates (which mostly get saved) and most long-term building projects (which couldn't even get started for a year or two).
A lot of people have absorbed the idea that stimulus should take the place of big, tangible works projects. Maybe it's all the New Deal imagery. But stimulus is basically about pouring money into the economy, in a way where it will keep flowing rather than congeal.