To the long list of rich-guy foibles that turned into defining campaign moments — John Edwards’s $400 haircut, John Kerry’s kite-surfing, John McCain’s inability to remember how many homes he owns — let us now add Newt Gingrich’s $500,000 revolving line of credit at the luxury jeweler Tiffany & Company. 
It has been a week since Politico broke the news that while working for the House Agriculture Committee, Mr. Gingrich’s wife, Callista, filed forms for 2005 and 2006 disclosing her husband’s “revolving charge” of $250,001 to $500,000 with Tiffany. Mr. Gingrich, insisting his jewelry buying habits are his own business, has declined to say what he bought.
As House speaker, Mr. Gingrich preached the virtues of fiscal conservatism; now he is struggling to explain how spending large sums on jewelry fits in with that philosophy. And while a spokesman for Tiffany confirmed Tuesday that Mr. Gingrich had paid the debt in full, with no interest, parrying questions about a six-figure jewelry bill is hardly what his campaign needs at a time when many Americans are out of work or have lost their homes.
The episode also reinforced what campaign strategists like to call “negatives” — in Mr. Gingrich’s case, questions about his personal life, which includes two divorces and a six-year secret affair with Mrs. Gingrich, then Callista Bisek, when she was a House aide and he was speaker.
The Gingrich campaign had hoped that, after 11 years of marriage, he could present himself as a stable family man. Now Mr. Gingrich is the butt of yet another round of late-night television infidelity jokes. “Five hundred thousand at Tiffany’s?” the comedian Stephen Colbert asked. “There’s a simple explanation. The guy clearly buys his engagement rings in bulk.” 
In Iowa, where Mr. Gingrich drew big crowds last week, The Iowa Republican, a political Web site, ran a scathing commentary titled “How a Fiscal Conservative Spends $500K at Tiffany’s.” The site’s editor, Craig Robinson, a former political director for the state Republican Party, said the essay was submitted by a political activist who was “completely turned off” by the expenditures.
“It’s bizarre; I don’t think he’s ever going to live it down,” Mr. Robinson said. “There aren’t many $500,000 homes in Iowa, so we can’t even fathom $500,000 in credit card debt, let alone to a high-end jewelry store.”