It reads like a nasty campaign attack ad, but it got our attention this morning. Credo Mobile, a cell phone company dedicated to social change, sent out an email making strong claims about its competitor, Verizon, a company currently basking in iPhone-related glory. Says Credo:

Unlike CREDO, Verizon plays the insider game in Washington and ends up donating money to right-wing politicians:

Verizon donated to the campaigns of Tea Party-backed Senators Rand Paul, Marco Rubio, Mike Lee and Pat Toomey.

It also gave more than $35,000 to members of the House Tea Party Caucus — most of whom are climate change deniers, voted to repeal health care reform, and have cosponsored a bill that would redefine rape.

Credo’s email doesn’t provide citations or references, but Fast Company reached out to Verizon, which confirmed the above as true. A spokesman read us a statement: “Verizon’s Political Action Committee supports a wide range of candidates, both Democratic and Republican, who indicate support for communications policies that are pro-consumer and encourage deployment, investment, and innovation in broadband and wireless technologies–policies, by the way, that are just as helpful to Credo Mobile’s business, as they are to competitors like Verizon.”

Opting for AT&T over Verizon won’t do you any better, iPhone-loving Tea Party-haters: it has donated $377,500 to members of the House Tea Party Caucus, according to Credo’s calculations.

Corporations, of course, donate money to politicians. Major corporations donate lots of it. In fact, in January of last year, a Supreme Court decision released a flood of new corporate spending on political ads, by overruling former decisions that had allowed the government to regulate such spending.

Corporations donate money to politicians they believe will advance their interest. The most recently published Verizon report on its political contributions runs the gamut, with both the Democratic and Republican parties represented abundantly. Pat Toomey is listed there, as the recipient of $2,000 of donations. Paul, Rubio, and Lee must have been supported in the wake of this report.

Sometimes, unseemly contributions can wind up working against a corporation’s interest. Last summer, for instance, Target sparked a boycott by donating generously to Republican Tom Emmer’s gubernatorial campaign. So fierce was the reaction that Target’s shareholders are considering a resolution on Target’s political activities. Some corporations, wanting to avoid such situations, ban political contributions entirely, as is the case with IBM.