NES has already taken a small step in the direction of adding aggregate data when, for a few surveys, it used congressional districts as the primary sampling unit. But this expensive step is not at all what I had in mind.
Congressional districts are a very high level of aggregation.
Their boundaries change frequently, and even the citizens of these areas are often not aware in which district they reside. The number of respondents NES can afford to survey in each district is too small to do much with. As important as congressional districts may be for some NES purposes, a sampling design based on them still miss most of American electoral politics. Once we get to this level of electoral geography, enormous quantities of information are available. The data for one precinct in one election year includes all vote totals for all offices in that precinct, and often much other information.