Bilbray, who has released three years of returns, more than Republican presidential candidate Mitt Romney, has used the tax-return issue in his contest against Scott Peters, a Democrat who has loaned his campaign $2 million.
“My attitude was, at least Romney released something,” Bilbray said. “Even if my opponent just released one, that would be a huge victory.”
Echoing Obama’s demands of Romney, candidates across the country have been calling on each other to publicly release their tax returns. It’s a tactic often used against incumbents and wealthier candidates, and it’s appeared in Senate races in Connecticut, New Jersey and Wisconsin.
The low-cost technique rarely backfires. Targets of such demands either release information that can be used by an opponent or refuse to offer details, which makes them look secretive.
The presidential race brought the strategy back “into vogue,” said Nathan Gonzales, deputy editor at the nonpartisan Rothenberg Political Report in Washington.
“Campaigns call on opponents to release tax returns if they think it will reveal something that will damage their opponent,” he said. “Depending on the attitude and aptitude of the local press corps, it could string out a story for days or weeks and keep your opponent hunkered down on an issue.”
Bilbray, 61, said he decided to make an issue of Peters’s tax returns after one of Peters’s primary election opponents did the same. He said it’s important for a self-financed candidate to disclose more information. Peters’s wife, Lynn Gorguze, is president and chief executive officer of Cameron Holdings Corp., a private equity firm.
“My wife doesn’t like all our financial laundry to be out there, but that goes with disclosure, that goes with transparency,” Bilbray said. “Once you start using your private finances as a political tool, you have an obligation, a political obligation, to disclose the source of that money.”
MaryAnne Pintar, a spokeswoman for Peters, said the tactic is a diversion by Bilbray, who is running in a district that’s less favorable to Republicans than his current constituency. She said the tax returns contain proprietary information that could be used by Gorguze’s business competitors.
“He’s raising it as a distraction from his record, which he doesn’t want to defend,” Pintar said.
Members of Congress disclose their finances every year. Candidates for Congress, including Peters, are required to report one-time snapshots of the net worth, investments, liabilities and transactions of themselves and their spouses. For incumbents and challengers, the amounts are reported in broad ranges that can make it difficult to get a complete financial picture.
There is no legal requirement that candidates release their tax returns, which are private.
The two documents provide different information about individuals, and tax returns can reveal details that people had never intended to make public, said Dean Zerbe, who analyzed the tax returns of presidential nominees when he was on the Republican staff of the Senate Finance Committee.
“You get a better, cleaner picture of their businesses,” said Zerbe, now a national managing director at Alliantgroup LP, a tax advisory firm. “It maybe just gives you a window into how they interact with the government: Are they playing it square?”
Candidates have embedded their demands for tax returns in larger narratives about their opponents.
“Both sides do it, and it really has a lot to do with where a candidate made his or her money,” said Jennifer Duffy, who tracks Senate races for the Cook Political Report.
Tammy Baldwin, the Democratic candidate for Senate in Wisconsin, has been seeking returns from Republican Tommy Thompson, saying the disclosure would provide needed information on his time as a Washington lobbyist.
In New Jersey, Republican Joseph Kyrillos released his returns first, followed by incumbent Senator Robert Menendez, a Democrat.
In Connecticut, Democratic Senate candidate Chris Murphy has used the tax returns of Republican Linda McMahon, former chief executive officer of World Wrestling Entertainment Inc. (WWE), to say that she would benefit from her own tax policies. McMahon has pointed to missed rent and mortgage payments by Murphy.
The best-known fight over tax returns has occurred in the presidential race. Obama, who has released tax returns dating to 2000, has demanded more information from Romney, who has released his returns from 2010 and 2011.
Obama has used the information in Romney’s returns to question what Romney is hiding and criticize the challenger for his low tax rate, which was 14.1 percent on $13.7 million of income in 2011.
Tax returns also allow for heightened analysis of tax policy, because voters can evaluate someone’s returns against their policy positions, said Joseph Thorndike, director of the tax history project at Tax Analysts, which has a compilation of presidential tax returns.
“It creates this teachable moment where it gives an abstract policy proposal or policy stance more immediate meaning to voters, and I think that’s meaningful,” he said.
Thorndike said the attention to Romney’s tax returns filtered into congressional races.
“It resonates, for whatever reason, with the public,” he said. “There’s that voyeuristic quality to it, like ooh, look at all this money.”
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