Republicans are hoping new election districts they drew last year and a wave of Democratic retirements help them strengthen their control of the Indiana Legislature.

Voters in Tuesday's primary are selecting Republican and Democratic nominees for all 100 Indiana House seats and half of the 50 state Senate seats.

The races include candidates in 19 House districts where no current legislators are on the ballot. Most are in Republican-leaning areas that the GOP hopes will help pad the 60-40 majority that allowed it to pass a contentious right-to-work law and a private school voucher law supported by Gov. Mitch Daniels despite boycotts by House Democrats the past two years. Republicans hope to gain a 67-seat majority in the House so Democrats can't block action with quorum-denying boycotts.

Despite decisions by a dozen of the 40 House Democrats to not run again, Democratic leaders say their candidates can successfully campaign on what they maintain were partisan overreaches by Republicans.

Former state Democratic Party chairman Kip Tew said the new election districts might be another kind of overreach that tried to lock in too many Republican seats.

"If you draw lines where you try to get too much, it can come back to bite you," Tew said. "You can get yourself spread too thin."

Few incumbent legislators are facing strong challengers. The pro-labor Lunch Pail Republican PAC is backing a handful of candidates in GOP races who oppose the right-to-work law, but it is uncertain whether any of them will be successful.

Republicans hold a commanding 33-17 majority in the state Senate. Primary races include freshman Sen. Susan Glick of LaGrange, who faces a challenge from Rep. David Yarde of Garrett in northeastern Indiana, and eight-term Democratic Sen. Earline Rogers of Gary, who is being challenged by a Hobart city councilman and the Gary school board president.

Both parties are sure to push hard in many districts for the Indiana House, which has been closely divided for most of the past decades before Republicans jumped to a strong majority with the 2010 election.

Former state Rep. Mike Murphy, a former Marion County Republican chairman, said he expected the new election maps will help the GOP gain some seats, but only with a fight.

"Just to say the Republicans are going to win 67 seats — it's not a lay-down hand," he said. "It is not a given."