He is known for legislation promoting democracy overseas, curbing the spread of weapons of mass destruction and isolating South Africa during the apartheid era.

But this election cycle, that doesn’t matter to Indiana voter Eric Krieg. “I don’t believe that foreign policy experience really matters. I don’t think that’s really on anybody’s radar,” Krieg said.

Jean Jacobson says Lugar is out of touch with voters like her, and she feels it is time for a change. “I don’t think he is as friendly as he used to be to conservative causes,” she said.

Purdue University political science professor James McCann says domestic concerns outweigh Lugar’s foreign policy experience.

“Indiana voters are typical of voters across the board in this country when you ask them what the most important issues are, they’re going to tell you the economy, they’ll tell you about jobs,” McCann said.

Eric Krieg agrees. He's an engineer at British Petroleum’s Whiting Refinery in northeast Indiana.

“This summer, at this oil refinery, there will be 10,000 people working. Tradesmen, pipe fitters, everyone making really good wages, making a good living,” Kreig said.

Krieg supports Lugar’s opponent, Richard Mourdock, a former geologist, because he wants greater energy independence for the U.S.

“This refinery has really become the premiere refinery in North America because of the oil coming from North Dakota now,” Krieg said.

Recent polling puts Lugar slightly ahead of Mourdock, but that gap is closing as the May 8th primary election draws near, influenced by conservative Tea Party voters backing Mourdock.

Purdue professor McCann says there is a downside if Lugar loses.

“You’d lose a fair amount of institutional memory in the Senate. You lose somebody who’s been an advocate for arms control; somebody who I think has some genuine bipartisan connections. In general I think the United States would lose a key spokesperson,” McCann said.

With Mitt Romney the likely Republican nominee for president, voter turnout in Indiana is expected to be low, and could influence who wins the primary.