Democrats justifiably screamed when Republicans instituted the infamous K Street Project designed to oust Democrats from top lobbying jobs and install Republicans who were expected to raise money and support GOP legislative aims.

Now that Democrats have regained power on Capitol Hill, there’s a whiff of K Street Projectism emanating from their side. It hasn’t reached the corrupting, intimidating dimensions put in place by former House Minority Whip Tom DeLay (R-Texas), but some Democrats may be stepping onto a slippery slope.

There’s been a lot of not-for-attribution grousing among Democratic leadership aides that trade associations, lobbying firms and corporate government relations offices haven’t hired enough Democrats, and last week some Democratic Senators even suggested there could be consequences if K Street doesn’t embrace the new majority in Congress.

“I think they haven’t come to terms with what happened two Novembers ago,” Sen. Bob Menendez (D-N.J.) said, adding that if lobby shops didn’t send up emissaries in policy sync with Democrats, they might find it “a little difficult at the end of the day for them to achieve the success they want.”

Similarly, Sen. Byron Dorgan (D-N.D.) said that “some organizations are so accustomed to being an adjunct of the Republican majority agenda, it’s hard to break those habits. To me, it’s not about how many Democrats are hired. It’s about how they weigh in on issues that are important to the country.”

And, on K Street itself, some Democratic lobbyists express hope that Democratic leaders will force firms to open top jobs for them. Said one unnamed lobbyist: “If Democrats want to hold the majority, they don’t do it by playing Mr. Nice Guy. You don’t hold power if you don’t know how to use that power.”

To the contrary, the reason Republicans lost power after 12 years was that they ran things as though keeping power was all that mattered. The K Street Project led to rampant earmarking to reward favored interests, which led to scandals and public disgust.

So far, Democrats haven’t tried to topple any Republican lobbyist from his perch, as DeLay did to former Rep. Dave McCurdy (D-Okla.). They are just complaining that firms such as Aetna hired a Republican.

We don’t find it too offensive that Sen. Harry Reid (D-Nev.) read the riot act to the National Association of Manufacturers about its support of conservative judges. Reid has a right to his opinion, as long as he doesn’t threaten massive legislative retribution.

Nor is it particularly objectionable, in and of itself, that top Democratic staffers try to get lobbyists to help them pass legislation such as the tax-extender bill — again, so long as threats aren’t part of the process.

But the lesson of DeLayism is that power corrupts, and corruption leads to defeat. Democrats need to heed the lesson.