(Bloomberg News) The largest U.S. private-equity funds and venture capital firms have relied on a five-year, multimillion-dollar lobbying campaign to protect the carried interest tax break that helped drive presidential candidate Mitt Romney's 2010 effective tax rate below 14 percent.

With the issue gaining attention in this year's U.S. presidential election campaign, the investment industry is again girding to defend its preferential tax treatment. Blackstone Group LP alone spent $5 million in 2011 lobbying Congress on issues including the tax treatment of carried interest.

"If anything preserves the status quo, it will be the very heavy lobbying campaign," said Edward Kleinbard, a law professor at the University of Southern California. "There's no other reason for the subsidy to survive."

Opponents of the tax rate for carried interest see this as an opportunity to press for change. Romney released his 2010 tax returns on Jan. 24, revealing he paid an effective tax rate of 13.9 percent on income of $21.6 million.

Romney, a former Republican governor of Massachusetts and co-founder of Bain Capital LLC, has come to personify the debate over whether the carried interest paid to private-equity managers should be taxed at the capital gains rate of 15 percent while ordinary income is taxed at rates as high as 35 percent.

Tax Fairness Debate

Democrats view the carried interest issue as an element of the tax fairness theme that President Barack Obama is highlighting in his re-election campaign. Representative Sander Levin of Michigan, the top Democrat on the House Ways and Means Committee, plans to introduce a bill as soon as this week that would tax carried interest at the same rate as regular income, according to spokesman Josh Drobnyk. The bill probably won't advance in the Republican-controlled chamber this year.

Carried interest is the profits-based compensation that private-equity managers, real estate investors and members of oil and gas partnerships often receive. They get a portion of their clients' earnings as investment income if the underlying earnings are treated that way. Levin and Obama call carried interest compensation for work, which they say should be viewed like wages for tax purposes.

Private-equity firms invested more than $148 billion in 1,234 U.S.-based companies in 2010, according to the Private Equity Growth Capital Council. The industry says it employs more than 8 million people.

Washington Lobbyists

Companies opposed to changing the tax treatment of carried interest have hired veteran Washington lobbyists to make their case. Wayne Berman of Ogilvy Government Relations is Blackstone's top lobbyist on the issue. He was an assistant commerce secretary during George H.W. Bush's administration. Other Ogilvy lobbyists working for Blackstone include Drew Maloney, who was a staffer for former House Majority Whip Tom DeLay, a Texas Republican, and Moses Mercado, the former House Democratic Leader Richard Gephardt's deputy chief of staff.

Kohlberg Kravis Roberts & Co. hired former Representative Vic Fazio, a California Democrat, to work with Congress on "tax issues affecting private-equity firms and their portfolio companies," according to lobbying records. The New York-based private-equity company spent $150,000 in the fourth quarter on lobbyists from Akin Gump Strauss Hauer & Feld to work on issues that included tax policy.

Bain spent $80,000 during the fourth quarter to hire lobbyists from Public Strategies Washington Inc. to "monitor tax reform developments," lobbying records show. Joseph O'Neill and Paul Snyder are lobbying for Romney's former company.

O'Neill was chief of staff to former Senate Finance Committee Chairman Lloyd Bentsen and helped run the late Texas Democrat's 1988 vice presidential bid. Snyder was a legislative assistant to former House Speaker Tip O'Neill, the late Massachusetts Democrat.

Budget Deficit

Raising taxes on carried interest compensation wouldn't do much to narrow the U.S. budget deficit. In its fiscal 2012 budget request, the Obama administration said the proposal to tax carried interest as ordinary income would generate $14.8 billion over 10 years. In December, the deficit stood at almost $1.3 trillion.

The issue has divided Congress along mostly partisan lines. The last time the Senate considered a bill that would have increased taxes on carried interest -- in June 2010 -- every Republican voted against it, preventing the bill from advancing. Senator Ben Nelson of Nebraska was the only Democrat to oppose the legislation.

Few Defections

The same bill was passed in the House that year with 15 lawmakers in each party voting against their leaders.

As the debate over carried-interest taxation advanced in Congress, the Private Equity Growth Capital Council was formed in February 2007 so the industry could make its case more directly to lawmakers.

The group, whose members include the Carlyle Group LP, based in Washington, and New York-based Blackstone spent about $2.5 million that year lobbying Congress on issues that included measures to tax carried interest at the same rate as ordinary income. It spent $2.2 million on lobbying in 2011.

"We believe that tax policy should incentivize the kind of entrepreneurial risk-taking that private-equity firms take every day," said Ken Spain, a spokesman for the Private Equity Growth Capital Council, a trade group based in Washington. "We remain vigilant in respect to this issue. Private equity as an asset class is going to be a topic of discussion throughout 2012."

Spain is a former communications director for the National Republican Congressional Committee.

Comprehensive Overhaul

While the issue will be a central one in the presidential campaign and on Capitol Hill, the taxation of carried interest probably won't change until Congress considers a comprehensive tax-code overhaul. That would be difficult to enact before 2013.

One potential challenge for private equity is something that otherwise would be seen as a favorable development for the industry: a Romney administration. Ending the preferential treatment of capital gains if Romney wins the presidency could dissolve notions that he is a captive to his former industry, said Martin Sullivan, a contributing editor at Tax Analysts, a nonprofit organization in Falls Church, Virginia.

"It will be much easier to repeal if Mitt Romney becomes president than if Mr. Obama remains president," he said.

Still, Romney adviser Eric Fehrnstrom told reporters last month that the Republican presidential candidate thinks carried interest should be taxed at the same rate as a capital gain. The candidate has proposed eliminating the tax on capital gains for those with adjusted gross incomes of less than $200,000 a year.

'Convoluted' Code

Private-equity executives also rely on fairness arguments to make their case. In a Jan. 27 appearance on Bloomberg Television, Steve Pagliuca, the managing partner of Bain Capital, said the tax code is "convoluted" and "almost unintelligible."

"We've got to have a fair tax code," he said. "We don't wake up every day saying 'Well, what's the tax code?' We wake up trying to build great businesses and we pay all of the taxes that are necessary."

Mark Heesen, president of the National Venture Capital Association, an industry trade group based in Arlington, Virginia, said his industry often reminds lawmakers of its differences from other investors such as private-equity firms. Venture capital firms typically invest in early-stage companies and don't use as much leverage as private-equity investors do.

Creating Something

"We are able to demonstrate our belief that quintessential capital gains are all about creating something out of nothing," he said. "That's what venture capital does."

Heesen said his message to Congress is that it's important to maintain the link between carried interest and capital gains, even if the capital gains tax rate increases. Unless Congress acts, such gains will be taxed at 20 percent in 2013. High earners will face an additional 3.8 percent tax on capital gains and other unearned income as part of the 2010 health-care law.

On the other side of the issue is the AFL-CIO, which has lobbied in favor of changing how carried interest is taxed, and is prepared to do so again. Damon Silvers, the policy director for the labor organization in Washington, called the treatment of carried interest a "tax subsidy for leveraged buyouts."

"We are going to be pressing the carried interest issue at whatever opportunity we get," he said. "Mitt Romney's tax returns are the world's greatest educational tool about the impact of the carried-interest loophole."

The AFL-CIO spent $1.1 million in 2007 to lobby Congress on issues that included a Senate bill to raise taxes on carried interest.

Lobbying on the carried-interest debate is only part of the reason the tax break has survived, said David Donnelly, the national campaigns director at the Public Campaign Action Fund, a Washington nonprofit group that tracks political contributions. Investors who are paid in carried interest are often the well-heeled donors that members of both parties turn to for campaign contributions, he said.

"I don't think it's simply the lobbying," Donnelly said. "The people who are interested in this particular provision are high net-worth individuals. That's a constituency that Congress always cares about when they have to raise money to fund their campaigns."