INDIANAPOLIS — Republican Mitch Daniels defeated former Democratic congresswoman Jill Long Thompson on Tuesday to win a second term as governor, but he may need a supply of olive branches to advance his agenda if Democrats retain control of the Indiana House.

Daniels wasn’t shy about advancing his call for change into a second term as he celebrated his victory with supporters at Conseco Fieldhouse about 9:30 p.m.

“The movement for change is moving ahead,” he declared.

“This is less an endorsement than an instruction, this is less a victory than an assignment,” Daniels said. “And what the people of Indiana have said is that they want us to press forward with change and improvement and reform to make education better, taxpayers better protected and make this the great state it can be.”

The call in the governor’s race was based on an analysis of voter interviews, conducted for The Associated Press by Edison Media Research and Mitofsky International.

Long Thompson conceded the race shortly after 9 p.m. A victory would have made her the first woman elected governor in Indiana history.

“This didn’t turn out as we had hoped, but we put a big crack in that glass ceiling,” she told supporters at the downtown Marriott in Indianapolis. “And it’s only a matter of time before that thing shatters here in Indiana.”

Daniels, a former policy adviser to President Reagan and President George Bush, had a huge fundraising advantage throughout the campaign and outspent his Democratic rival by at least $10 million.

Democrats had hoped to capitalize on the momentum of Barack Obama’s presidential campaign and voter unhappiness over changes in Daniels’ first term, which included decisions to observe daylight saving time statewide and lease the Indiana Toll Road to a foreign venture.

Many of those changes came during his first two years in office, with help from a House then controlled by Republicans.

Democrats regained the House in 2006 but held a 51-49 edge that left open the possibility that Daniels could again find friendly territory in House chambers after Tuesday’s votes were tallied. As of about 10:30 p.m., each party had won 42 seats, according to unofficial tallies by The Associated Press, but several key races remained close.

Republican Ed Clere of New Albany beat Rep. William Cochran of New Albany by 114 votes for a seat the Democratic incumbent had held since 1974.

Former Democratic Greencastle Mayor Nancy Michael beat Rep. Amos Thomas, R-Brazil, in District 44, and Democrat Mary Ann Sullivan defeated Republican Rep. Jon Elrod in District 97 in Indianapolis. Republican Mark Messmer of Jasper won an open District 63 seat being vacated by Rep. Dave Crooks, D-Washington.

Senate Republicans, meanwhile, went into Election Day with a 33-17 advantage and election results showed them keeping at least 32 seats. They have controlled the chamber since late 1978.

Even with Democrats controlling the House the past two years, Daniels won approval of a cigarette tax increase to create a new health insurance program for low-income residents and a major property tax relief and restructuring package.

His agenda for a second term includes further expansion of full-day kindergarten, taking the next step toward amending property tax caps into the state constitution and keeping the budget balanced — which he says is his top priority given the tanking economy.

He has suggested that will be easier to accomplish with a GOP-controlled House, calling Democratic House Speaker Patrick Bauer of South Bend “an expensive date.”

Long Thompson had blamed Daniels for thousands of jobs Indiana has lost this year and had pledged to overhaul the state’s tax structure and implement a new economic development program to boost the economy.

She also had promised to restore bargaining rights for state employees, which Daniels rescinded on his first day in office, and end what she called Daniels’ “privatization madness” that she said had resulted in bad financial deals and worse services.

Outcomes in about a dozen House races were likely to determine which party would yield the gavel in 2009 and 2010.

All 100 seats in the House were on the ballot, with 44 Democratic incumbents and 43 Republican incumbents seeking re-election. Eighteen Democrat candidates and 16 Republicans — including one for each party running in 13 open-seat contests — faced no major party challengers.

Twenty-five of the 50 Senate seats are on the ballot, with eight candidates unopposed. Republican Jean Leising of Oldenburg won back her seat after years out of office, and Democrat Lonnie Randolph from East Chicago was expected to do the same.