When Howard Cain was working a closely contested legislative race in 1993, he made sure to carry a wad of $10 bills in his pocket on Election Day.

Why? At the time, you could challenge the legitimacy of an absentee ballot at the polling place with a $10 deposit.

It's the kind of intimate knowledge of the political process that Cain was known for in a 28-year career that now stands jeopardized by his guilty plea yesterday on tax-evasion charges.

"I think what stands out about me is that I don't stand out," Cain said yesterday, reflecting on his years as a political consultant. "I've always tried to be low-key, the fat guy standing in the corner."

It's a description that rings true with politicians and journalists used to seeing Cain, a stout man with a bald spot, standing in the wings of political events, usually wearing a suit with suspenders.

Cain offers political wisdom discreetly, often delivering it with a dry sense of humor.

"He knew his business," said Philadelphia Record publisher Jimmy Tayoun, a veteran Democratic pol. "He ran my [1984] campaign for Congress. He was strictly business. He'd open up his briefcase, and he'd have all those maps and calendars. He was very meticulous."

A suburban kid with a political-science degree from Villanova, Cain got a taste of politics when he helped a friend run for state representative in Roxborough in 1976. He discovered that he had a talent for demographic and statistical analysis of voting trends in the pre-computer age.

He worked for other candidates, and, while working in a 1982 state Senate campaign, met Vince Fumo, whom Cain called "probably the smartest politician I've ever known."

"I think I was the first guy working for him who wasn't from South Philadelphia." Cain said.

The two began a collaboration that lasted 22 years. Cain worked on dozens of political campaigns, while also consulting with unions and working on campaigns to block changes in the city charter and to get more money for mass transit.

He worked mostly for Democrats whom Fumo supported, though in 1999 he advised Republican mayoral candidate Sam Katz.

Cain declined to discuss why he and Fumo parted ways in 2004, and also declined comment on his criminal case. *