Just to cut to the chase: researchers sent letters to more than 190 members of Congress, asking for a meeting. When they introduced themselves as donors, they were more than five times more likely to get the meeting than when donations weren't mentioned. And those meetings were usually with more senior staffers.
That's from a study conducted by researchers from Yale and Berkeley aimed at determining if political donations increased access to elected officials. The answer was clear: it does.
The set-up was simple. Working with the progressive group CREDO Action, Yale's Joshua Kalla and Berkeley's David Broockman wrote emails asking members of Congress for a meeting. On a third of the emails, the letter requested the meeting on behalf of "active political donors;" on the other two-thirds, the request was for a meeting with local constituents. And:
When it was constituents asking, the people in the meeting got to meet mostly with lower-ranked district staff. (The meetings actually happened, by the way, without the participants knowing how they'd been scheduled.) When it was donors, members of Congress were more likely to provide heavy hitters. Donors, for example, were four times more likely to get to meet with the member of Congress directly.