By Wendy Koch, USA TODAY Thu Nov 10, 7:17 AM ET

Michael Sessions is too young to drink champagne legally, but the 18-year-old high school senior has reason to celebrate: He unofficially won a race for mayor Tuesday by defeating the baby boomer incumbent.

Sessions, who turned 18 on Sept. 22, ran as a write-in candidate because he was too young to get on the ballot in the spring. The young politician used $700 from a summer job to fund his door-to-door campaign in Hillsdale, Mich., a town of about 9,000.

Unofficial results show that Sessions got 732 votes, compared with 668 for Mayor Doug Ingles, 51. Once his victory is certified and he's sworn in - the ceremony is set for Nov. 21 - he may be the youngest mayor in the USA. The U.S. Conference of Mayors lacks the data to determine whether he'll be the youngest mayor ever, says spokeswoman Elena Temple.

At least two other teens have been elected as mayors in recent years, but they were a tad older and represented much smaller towns. Jeffrey Dunkel was one month shy of 19 when he was sworn in as mayor of tiny Mount Carbon, Pa., in January 2002, and Chris Portman was 19 at his inauguration in Mercer, Pa., the same month.

"I've always been interested in politics," says Sessions, who registered to vote the day after his birthday and became a write-in candidate one day later. "It's certainly hard to be a write-in candidate," he says, adding that he drove around town Tuesday afternoon, nervous that people didn't know his name.

He says many voters told him they wanted "new energy," but he was still caught off-guard by the support he received.

"He was a real go-getter during his campaign," says Steven Brower, a government and economics teacher at Hillsdale High School. "He acted like he was running for president."

Brower, who gave his former student campaign tips, says he's thrilled: "There are too many kids today who laugh at government." He says Sessions, by carefully researching issues before taking a position, will serve responsibly in the largely ceremonial, four-year pos.

The job comes with no office, no chair, no filing cabinet - not even a drawer, says incumbent Ingles. The mayor, who gets a $250 monthly stipend, casts one of nine votes on the City Council.

Ingles, who runs a roller-skating rink, says he's not upset by his loss. "It's an honor to serve. I'm proud of that," he says.

Dunkel says the toughest part of being a young mayor was getting people to take him seriously. After he proved he could do the job, by getting a police protection grant in his first year, he says residents came around. He won re-election this week.

Sessions says his parents were skeptical at first but are now "very supportive." He says he has no agenda but wants to meet everyone. "I'm trying to set up a board of advisers" that will include a former mayor and leaders from Hillsdale College, which he hopes to attend next fall.

Sessions plans to devote after-school hours to the job and use his bedroom as his office