I began writing, as a liberal, against the estate tax in 1994. In my mind, the tax is complex, unfair and inefficient. Those who plan around it can easily avoid it, but even when it does fall on the wealthy, it falls on the wrong wealthy—those who work hard and save well, not the self-indulgent who spend it all and die broke. I have testified about it in Washington and spoken about it on talk shows, and I always feel like Bill Murray’s character in Groundhog Day who keeps living the same day over and over again. In the run-up to the last congressional vote on the bill, every six months some breathless assistant at an NPR affiliate would call to ask me to debate estate-tax repeal. I would calmly explain what a bad tax it is, while some well-meaning liberal guest would go on about its crucial necessity. The host would end by asking me what would happen next. "Nothing," I would say, "and we’ll talk again in six months." And so we would.

Ever since Mancur Olson wrote The Logic of Collective Action in 1965, the dominant view of legislation has centered on special interest groups. In the traditional view, small groups with high stakes arise independently, motivated by a common interest and able to solve the "free-rider" problem of collective action. These special interests then descend on Washington, seeking legislative goodies.

In my mind, the tax is complex, unfair and inefficient.

But in an era of rapacious desires for campaign war chests, this traditional understanding of politics is often precisely backward. At least in an important set of cases, lawmakers themselves, addicted to the money that special interests provide, actually give birth to the very special interests that later plague them—and then these lawmakers string the groups along. Special interests become the victims of the political process; they become the prey, rather than the predators.

The estate tax provides a perfect case study. Beginning in the mid-1990s, momentum built for bills such as the Death Tax Elimination Act, a law that actually passed both the House and Senate only to face an expected veto from Bill Clinton in 2000. But the mere possibility of estate-tax repeal was a dream come true for lawmakers: Here is a tax falling on a very few people, but at high stakes. Private parties who someday expect to incur the tax will rationally pay lawmakers to kill the tax. On the other side, parties that benefit from the existence of the tax—insurance companies, lawyers, accountants and sophisticated nonprofits—rationally pay to keep it. Congress has perfect shakedown territory.

This new understanding of politics suggests that Congress will milk this cash cow for all it’s worth, voting over and over and coming up just short of a permanent repeal. And so it has—in spades. In my academic work, coauthored with political economist Linda Cohen, we show how senators flip their votes to keep repeal efforts under the needed 60 votes, and how Republicans played an essential role in defeating the death of the death tax. On every critical vote, Republicans joined the minority blocking the requisite 60 votes. Even at the height of his popularity, President Bush was unable to sway the few votes needed for repeal. Most damning of all, Republicans failed to take advantage of any window in which they could have killed the death tax with 50 votes. Meanwhile, Democrats, also reaping campaign contributions from the ongoing brinkmanship, unapologetically switched sides, making sure that the issue of the death tax would live for another day of campaign-contribution-fueled "debate."

I predict, as I have for years, that Congress will settle on a compromise of something akin to a $3.5 million to $5 million exemption, and a 35 to 45 percent rate—something that could have happened yesterday, to paraphrase Adam Sandler’s character in The Wedding Singer. But not to worry: The issue will live on . . . and on. And soon there will be more votes to kill the tax.

Edward J. McCaffery, author of the book Fair Not Flat: How to Make the Tax System Better and Simpler, is an attorney with Sonnenschein Nath & Rosenthal in Los Angeles and holds the Robert C. Packard Trustee Chair in Law, Economics and Political Science at the University of Southern California.