Even if he weren't running for re-election in November, the Walgreen Co.'s flirtation with a tax-friendly Swiss headquarters would have been a fat pitch for Illinois Democratic Sen. Dick Durbin.

Happily for Mr. Durbin, Walgreen's timing couldn't have been better. As part of its plan to acquire the 55 percent of Swiss-based drugstore chain Alliance Boots that it doesn't already own, Deerfield, Ill.-based Walgreen was considering one of the infamous "inversions" that have become increasingly popular in corporate America.

In an inversion, a U.S. company buys a smaller company in a nation where the corporate tax rate is lower than the putative 35 percent U.S. rate. The headquarters for the merged entity is established overseas, allowing the U.S. company to lower its worldwide tax bill.

Some 41 firms have established overseas tax domiciles since 1982, 12 of them in 2012 alone. Eight more are considering it. Most of them book most of their profits on intellectual property, like drug patents. Walgreen, however, runs 8,116 highly visible retail stores, making them vulnerable to consumer backlash.

Last month, Mr. Durbin began waving the Stars and Stripes at Walgreen, writing in a letter to the company CEO that, "I believe you will find that your customers are deeply patriotic and will not support Walgreen's decision to turn its back on the United States. Nearly all of your $2.5 billion in profits earned last year were from sales to U.S. taxpaying customers."

Mr. Durbin also reminded the firm of a truth that lots of corporate executives like to forget: They benefit hugely from U.S. taxes. In Walgreen's case, 25 percent of its profits came from taxpayer-supported Medicare and Medicaid programs.

In addition, he pointed out that "Walgreen's uses taxpayer-supported transportation infrastructure to stock its stores and deliver its products. Your company benefits from our country's investment climate and educated workforce, and you and your fellow executives have benefited from tax breaks on compensation packages. If you and Walgreen's board of directors decide to invert to avoid U.S taxes, you will be turning your backs on the very people that have allowed Walgreen's to thrive and prosper."

With a dig at Walgreen's advertising slogan, Mr. Durbin added, "Is 'the corner of happy and healthy' somewhere in the Swiss Alps?"

Last Wednesday, Walgreen announced that the headquarters of the new holding company, Walgreen's Boots Alliance, would be in Illinois. Moving to Switzerland, the firm said, would not be in the long-term best interests of shareholders. Short term, shareholders immediately began dumping the stock, which closed down 14 percent. So much for Wall Street patriotism.

Even better for Mr. Durbin, his Republican opponent in the November election, state Sen. and dairy executive Jim Oberweis of Sugar Grove, immediately accused him of "bullying" Walgreen. Mr. Oberweis did not specifically endorse tax-dodging, a fine point that may be lost during the fall campaign.

In fact, the United States does have the highest corporate tax rate among developed nations. Also in fact, almost no corporation pays the full 35 percent. More than 90 percent of all U.S. corporations are so-called "pass-through" entities where business income is treated and taxed as personal income.

Large public corporations can take advantage of any number of loopholes, deductions and tax havens; the Government Accountability Office reported last year that the average effective corporate tax rate was 12.6 percent, lower than many middle- and upper-class families pay.

Democrats and Republicans in Congress generally agree that the tax code needs reform, but as with so many other things, can't agree on how to do it. Everyone wants a lower tax rate, but no industry wants to give up its bought-and-paid-for tax loopholes.

President Barack Obama has proposed lowering the corporate rate to 28 percent while trimming some of the special exemptions. Mr. Obama also wants Congress to limit the corporate inversion scam. He said this month:

"We don't want companies who have up until now been playing by the rules suddenly looking over their shoulder and saying, 'You know what, some of our competitors are gaming the system and we need to do it, too.'"

If Congress doesn't act — and these days, that's a given — the Treasury Department could take steps on its own to make the deals more difficult.

Too many multinationals have found ways to book U.S. earnings as foreign profits, stashing them overseas as part of the $2 trillion in overseas profits that can't be taxed until they're repatriated. All of this means that the average U.S. taxpayer has to make up the difference, or critical needs go unfunded.

What's good for Wall Street often is not good for Main Street. Given the differences between Mr. Durbin and Mr. Oberweis on this issue, this debate could get a useful airing in Illinois this fall.

REPRINTED FROM THE ST. LOUIS POST-DISPATCH