Alexi Giannoulias’ last run for office — in 2010, for President Barack Obama’s former U.S. Senate seat — ended in stinging defeat that halted his political career.

Until Tuesday, at least, when Giannoulias, a Democrat, formalized his planned comeback, with a dominant win over Republican Dan Brady in the election for Illinois secretary of state.

Giannoulias replaces the retiring Jesse White to run a state agency responsible for driver’s licenses and motor vehicle registrations — and known historically as a launching pad for even higher office.

With more than 47% of precincts reporting, Giannoulias had roughly 59% of the vote to around 39% for Brady, a veteran state legislator from Bloomington. Libertarian Jon Stewart had 2%.

Brady’s spokeswoman says her candidate conceded Tuesday evening, before Giannoulias spoke to supporters, declaring victory.

“Don’t ever let anybody count you out, don’t ever let anybody say you’re finished,” he told a cheering crowd, at times appearing to choke back tears. “Thank you for believing in me once again.”

Giannoulias, a 46-year-old resident of the Near North Side, will be sworn in Jan. 9.

In what came across as a subtle critique of White’s nearly 24-year tenure, Giannoulias and Brady, 61, each spoke during the campaign of the need to “modernize” the agency.

Giannoulias has said he wants to give drivers the ability to schedule appointments online to skip what are often frustratingly long lines at secretary of state facilities.

He floated the idea of creating digital — rather than just physical — driver’s licenses and state identification cards.

Brady proposed cutting some fees, allowing electronic filing of some vehicle information and opening secretary of state outposts at community colleges.

Beyond the ideas that emerged, Giannoulias faced tough criticism during his primary and general election — with much of it echoing what he’d faced in 2010 in his loss to Republican Mark Kirk in the U.S. Senate race.

While serving as state treasurer from 2007 to 2011, Giannoulias’ office oversaw a college-savings program that lost tens of millions of dollars because of risky investment decisions by the fund manager.

His family’s Broadway Bank, where he’d worked, also made questionable loans to reputed organized crime figures — before collapsing in 2010 at a cost to the Federal Deposit Insurance Corp. of hundreds of millions of dollars.

The Chicago Sun-Times reported last year that, for this race, Giannoulias accepted campaign donations from four top officials of the bank. Among them were his two brothers, who ran the bank, which federal regulators shut down over losses that included more than $100 million in bad loans made to 17 failed commercial projects from New York to Los Angeles.

Giannoulias’ campaign was well funded, raising more than $3 million from July through September alone — including $1 million from Gov. J.B. Pritzker’s political fund, records show.

Giannoulias’ campaign also accepted campaign donations from the Service Employees International Union, including a political-action committee for Local 73, which represents secretary of state employees.

Giannoulias apparently will continue to accept those types of donations, but has pledged as part of an ethics package not to accept contributions directly from employees or contractors of the agency.

The secretary of state post was long coveted by politicians because it came with patronage jobs — though these days there are just over 100 “at-will” employees out of a workforce of nearly 4,000. And the position has been considered a stepping stone to higher office, with Jim Edgar and George Ryan both serving as secretary of state before becoming governor, and Alan Dixon serving as secretary of state before becoming a U.S. senator from Illinois.

Asked during a WTTW forum last month whether he’s running for this job so he can eventually springboard to another elected office, Giannoulias said: “No, I’m very excited about this opportunity, it’s the only office that I’d run for.”