Indianapolis — Indiana’s hotly contested Republican Senate primary race has generated more than $12 million in campaign spending, including a record-topping $4 million in outside dollars.

The intra-party fight between incumbent U.S. Sen. Richard Lugar and his challenger, State Treasurer Richard Mourdock, has also attracted the rapt attention of the national news media who’ve dubbed it the marquee race to watch.

But so far, all that money and media coverage hasn’t made voters eager to vote, according to one indicator: Early voting — including the number of absentee ballots requested by Hoosier voters for Tuesday’s primary — is down significantly from years past.

“We’re way behind,” said Indiana Secretary of State Connie Lawson, who serves as the state’s chief election officer.

No one expected a repeat of the blow-out numbers in 2008, when then candidates Barack Obama and Hillary Clinton were in a virtual arm-wrestling match for the Democratic presidential nomination. The state set a record for primary voting - early, absentee, and otherwise.

But this year’s early voting numbers are lagging behind the 2010 and 2006 primary voting numbers as well.

As of May 1 — just past the deadline for applying for an absentee ballot by mail - 48,946 Hoosiers had requested an absentee ballot for Tuesday’s primary election.

That’s about 30,000 less than at the same point two years ago, when 79,228 Hoosiers had requested an absentee ballot for the 2010 primary election. In 2006, more than 61,000 Hoosiers cast the their primary ballot by absentee vote.

Lawson cast her vote early, by absentee ballot, last weekend since she plans to be busy Tuesday visiting vote centers and monitoring the election. She’s not sure why others aren’t following suit.

But some people who study politics think there is combination of forces at work, ranging from the lack of contested races to the revulsion of voters.

Political scientist Andrew Downs, director of the Mike Downs Center for Indiana Politics at Indiana University-Purdue University Fort Wayne, said there’s not much primary competition in many of the contests for state and local offices.

He notes, for example, there are 100 seats in the Indiana House of Representatives, but only 30 where Republicans are vying against each other; there are only 13 state House races with Democrat contests.

But he suspects there’s more to it. He thinks the overheated rhetoric of political campaigns nationwide may be proving toxic for some voters.

“It is so combative,” Downs said. “There is a surprisingly large number of people who think it’s damaging to the electorate.”

Ed Feigenbaum, publisher of Indiana Legislative Insight, has been surprised by the low early turnout.

It’s not what he expected; in addition to the noisy and expensive Lugar-Mourdock race, there are at least two U.S. congressional races where the primary victor will be the champion in the fall election.

“I wonder whether people are simply turned off by the negative campaigns or whether they may be undecided and don’t want to vote until they have a better idea as to whom they should vote for,” Feigenbaum said by email.

Political scientist Michael Wolf of the Mike Downs Center for Indiana Politics has been studying voter behavior in recent elections. He’s found that while some voters are turned off by bitter politicking, many others are turned on.

Research he did in the 2010 elections nationally found that people who identified themselves strongly in partisan terms and who see compromise as a vice rather than a virtue responded to political vitriol in a positive way: They were the ones who turned out to vote.

“There was a huge plurality (of voters) who were mobilized by incivility,” he said.

Based on his research, Wolf’s prediction is this: Don’t expect political campaigns to get any nicer anytime soon.

Maureen Hayden covers the Statehouse for the CNHI newspapers in Indiana. She can be reached at maureen.hayden@indianamediagroup.com.