Jay LaPrete, File, Associated Press
FILE - In this Nov. 2, 2010 file photo, Ohio Treasurer of State-elect Josh Mandel, right, celebrates his win with his wife Ilana at the Ohio Republican Party celebration in Columbus, Ohio. Mandel has moved through his first year as a statewide officeholder with the ease of his generation. At 34, he spends much of his day on his cell phone. He pays keen attention to his Web presence, often attends state meetings remotely, and launches into brainstorms with aides during off hours.

COLUMBUS, Ohio — During his first year as state treasurer, Ohio Republican Josh Mandel has been a man between two worlds, balancing duties of his first statewide office with a fledgling U.S. Senate campaign.

Mandel has aggressively worked the fundraising and speaking circuit these past months, amassing more than $3.8 million this year in his Senate bid against Democratic incumbent Sherrod Brown. That's perhaps more than any other Senate challenger in the country.

At the same time, his weekly calendars as state treasurer are almost devoid of appointments outside of staff meetings and speaking engagements. And he's yet to hold a single news conference to discuss the work he's doing for Ohioans.

Mandel, a Jewish Republican and two-tour U.S. Marine veteran who married into a well-connected Cleveland family, has emerged as one of the most ambitious young politicians in a closely divided battleground state.

Campaign filings reviewed by The Associated Press show Mandel's first post-inaugural campaign flight of the year may have come as early as Feb. 7, less than a month after he took office. A spokesman for his campaign declined to say who on the campaign staff took a flight logged on that date, one of several during the early months Mandel was in office.

"During the first quarter of 2011, we tried to err on the side of caution and use campaign funds rather than taxpayer funds to pay for travel that may include both political and non-political discussions," said spokesman Joe Aquilino.

Known locations of Mandel's Senate fundraising destinations include Washington, D.C.; New York; San Francisco; Chicago; and Hawaii.

Mandel, whose wife Ilana is a millionaire, has never officially told Ohioans he wants to be elected in November as one of their two U.S. senators. Instead, the news has leaked out bit by bit through federal filings and word of mouth.

Critics say Mandel has little to show for his time as state treasurer because he's been so focused on his federal campaign. They say he's afraid to face reporters at a news conference because they'll question his promise to serve his full four-year term as treasurer and ask about his experience level for higher office.

Mandel dismisses such attacks. At 34, he moves through his days with the ease of his youth — coatless in a white business shirt, and carrying a bottled water.

He knows most employees he passes in the hallways by name, and often inquires about their vacations, health or family lives. At a recent monthly meeting of the office's program directors, Mandel got swiftly to his points: Do you need more staff? How's that new manager working out? Where does that lawsuit stand?

But Mandel lives in a wired world, doing much of his business by cellphone. Spokesman Seth Unger concedes "he's not one who likes to spend time behind a desk, that's not his style." Mandel often attends state meetings remotely, he pays keen attention to his web presence, and he'll engage in sudden brainstorms with aides on a random weeknight or Saturday.

But Mandel disputes those who say he's ignoring his job as treasurer. He notes he called for an attorney general's investigation in June into manipulation of foreign exchange rates at the state's pension and injured worker funds, successfully divested the state treasury of foreign debt in the wake of the European financial crisis, and completed an efficiency review of the office that's saving taxpayer dollars.

"When I came in here, I took the position that we were going to try to run the office quietly, humbly, keep our head down and do our job," he said in a recent AP interview.

He contrasted the approach to that of Democrat Richard Cordray, a predecessor in the office who was criticized for his large communications staff.

The Ohio Democratic Party, in its efforts to defend incumbent Brown, has criticized Mandel all year for launching a behind-the-scenes Senate bid after promising publicly to serve his full four-year term in state office.

Justin Barasky, who follows Mandel's activities for the Democrats, lampooned Mandel's first 100 days in office in a calendar released to the Statehouse press corps. It began on his first day in office with the note-to-self "Sworn in! Yes!" The next day, it said, "Be a 'Darn Good' Treasurer, 4-8 years." The next, "Engineer 'Draft Mandel' Movement — Don't 4get to Act Surprised!" Later in the year, the calendar quips: "Be a 'Darn Good' Treasurer, 4-8 days."

Barasky said Mandel has ignored his duties as treasurer to traverse the country pursuing his Senate bid.

"Ohio deserves better than an absentee treasurer who only cares about one job in Ohio: His next one," he said.

Mandel's weekly calendars, provided to the AP through a request, show only a rare meeting representing the state with an individual guest or group.

One of the few sitdown appointments he logged was a June 3 meeting with a foursome that included former Republican National Committee chairman Ken Mehlman and former Democratic U.S. Rep. and presidential contender Dick Gephardt, now a Washington lobbyist. A spokesman said the meeting involved treasury business. Mehlman is now a member of the private equity firm Kohlberg Kravis Roberts & Co.

Unger said Mandel "isn't one who likes to sit behind a desk," but that taxpayers get more than their money's worth from his around-the-clock working style.

"The guy works 60, 70 hours a week, that's on the low end of what he's putting in seven days a week," Unger said.