House Democrats are considering filing an ethics complaint against Financial Services Chairman Mike Oxley (R-Ohio) for allegedly pressuring mutual fund companies to fire a Democrat as their chief lobbyist and hire a Republican. The evidence is strong enough that they should stop considering and do it.

If Democrats do move forward, they would be breaking the six-year truce between Republicans and Democrats that ended the ferocious ethics wars of the late 1980s and early 1990s that toppled Speaker Jim Wright (D-Texas) and undermined his pursuer and future Speaker Newt Gingrich (R-Ga.). Under the deal, one party doesn’t file against a Member of the other party unless egregious offenses are involved, usually involving a criminal probe.

As exposed in a well-documented story in The Washington Post on Feb. 15, pressure tactics employed by Oxley’s staff upon the Investment Company Institute cry out for an ethics investigation. The Post reported that six sources, Republican and Democratic, told them that two members of Oxley’s staff had told ICI companies that his committee would ease up on an investigation of the mutual fund industry if ICI fired Julie Domenick, a Democrat, as its top lobbyist and hired a Republican in her place.

If true, this conduct is extortion, pure and simple — Tony Soprano tactics, as the Post correctly opined in an editorial. It also violates House and government ethics rules, which prohibit Members and their staffs from “bestowing benefits on the basis of the recipient’s status as a supporter or contributor, or partisan affiliation” or from using their position “to coerce or induce another person … to provide any benefit, financial or otherwise.”

As nearly everyone on Capitol Hill knows, application of pressure on firms and associations to find plum lobbying jobs for political friends is next to routine. But it’s been institutionalized by Republicans in the form of the “K Street Project,” run out of the Republican National Committee, which lists openings in lobbying firms and monitors the hiring process to make sure GOP applicants are favorably considered.

In 1998, the year after the post-Gingrich truce was declared — but before it became sealed in concrete — the House ethics committee admonished then-Majority Whip Tom DeLay (R-Texas) for trying to pressure the Electronics Industry Alliance not to hire Democratic former Rep. Dave McCurdy (Okla.) as its president. That precedent alone should inspire Democrats to break the truce.

If Democrats file against Oxley, it’s possible Republicans will file complaints against two Democrats accused of wrongdoing. Rep. Paul Kanjorski (Pa.) has been accused of steering federal contracts to a family business. Rep. Jim Moran (Va.) accepted a loan from a bank whose priority legislation he then sponsored. These cases deserve investigation, too.