The House Ethics Committee has cleared Maxine Waters of wrongdoing in a celebrated but thin case over whether she improperly set up a meeting between the Treasury Department and a troubled bank in which her husband had a stake. Her chief of staff (and grandson), Mikael Moore, still faces scrutiny. But Waters “went above and beyond what was required of her,” according to one Republican on the committee.

The findings, which still must be acted on by the Ethics Committee, represent some of the final steps in what has been a three-year investigation into Ms. Waters’s actions during the financial crisis. In the fall of 2008, Ms. Waters called Treasury officials to set up a meeting that included officials from a bank her husband owns stock in. The bank, OneUnited, based in Boston, was near collapse.

The investigation itself has been mired in controversy after the House Ethics Committee’s own chief counsel accused staff members in 2010 of sharing confidential details about the matter with Republicans, a violation of House rules. The result was an extraordinary outside investigation by a former Justice Department prosecutor who was appointed first to see if the Ethics Committee itself had acted improperly before restarting a new inquiry into the accusations against Ms. Waters.

This second investigation concluded that Ms. Waters did not act improperly in setting up the meeting, as she believed when she did that the meeting was on behalf of all minority-owned banks, not just OneUnited, Billy Martin, the special investigator said at a public hearing on Friday morning. This was an argument that Ms. Waters has long made.

I actually looked into this a long time ago, comparing the situation with Waters to the one with Charlie Rangel, who was reprimanded in his ethics case. The evidence always supported Waters’ case that she asked for a meeting between Treasury and executives from minority-owned banks, not just OneUnited. The trade group for minority-owned banks produced letters showing that Waters acted on behalf of all of them generally. Waters also disclosed her ties to OneUnited, through her husband, in open testimony in Congress back in 2007.

The larger issue at play here is that, with the retirement of Barney Frank, Waters stands to be the senior Democrat on the House Financial Services Committee. And bank lobbyists and their allies in Congress don’t want that. That’s because she actually advocates in the interest of people over bank executives. You can see this from the fact that, a day after Waters destroyed big bank arguments over foreclosure fraud in a House hearing in late 2010, “new documents” just magically came to light in the ethics case. Obviously these new documents amounted to nothing.

Wall Street will just have to be content with the fact that the top Democrat on the committee with jurisdiction over them in the House isn’t completely bought off.