Pretty much all of them get lobbied in some way, but the scale varies a lot. In Washington, the basic rule of thumb is that there are roughly 20–23 registered lobbyists per member of Congress , so every senator and representative is part of a very crowded influence environment.

What that means

  • Congress has 535 voting members total, and lobbying is aimed at both chambers, committees, and key staff, not just the lawmakers themselves.
  • OpenSecrets describes lobbying as a major federal influence system, with organizations spending billions each year to try to shape legislation and agency action.
  • Because of that, it is fair to say almost every member of Congress is lobbied on the issues that matter to them, especially if they sit on a powerful committee or handle a high-stakes topic.

Senators vs. House members

  • Senators are usually lobbied heavily because they vote on national issues, confirmations, treaties, and big policy fights.
  • House members are also heavily targeted, especially committee chairs, ranking members, and members from swing districts.
  • Lobbying is often concentrated where one vote, one amendment, or one committee decision can move a bill.

A useful nuance

“Lobbied” does not just mean a lobbyist physically meets the politician. It can include calls, emails, fundraisers, policy briefings, meetings with staff, and pressure through allied groups. So even if a lawmaker never meets a classic downtown lobbyist face-to-face, they may still be receiving constant lobbying attention.

Bottom line

Your guess is basically right: nearly all members of Congress are lobbied , and the real question is usually how intensely, by whom, and on what issues.

Question| Practical answer
---|---
How many are lobbied?| Almost all members of Congress 34
How much pressure is there?| Roughly 20–23 lobbyists per member of Congress 359
Is it just Congress?| No, lobbying also targets agencies, staff, and the broader federal policy process 4

TL;DR: Yes — basically all of them. The U.S. lobbying system is so large that almost every senator and representative gets targeted regularly.