INDIANAPOLIS — When major party candidates for governor in Indiana announce the choice for their lieutenant governor running mates — or when word leaks out — it almost always makes a big splash in the media.

That’s in part because it usually ends weeks of speculation by political observers, including reporters, on who will complete the team and how that person might help the gubernatorial candidate win.

Indeed, running mates might influence the choice that some people make when voting for governor. But is it a big factor for most voters? Probably not.

“It’s not a significant kind of election-changing choice, like this means someone will win,” said Ed Feigenbaum, a political analyst and a former staff director for the National Conference of Lieutenant Governors. “People make decisions on the merits of the person leading the ticket.”

Feigenbaum said the first rule in selecting a running mate is picking someone who will do no harm — and who will not overshadow the principal candidate.

Mitch Daniels got gobs of publicity when he chose Republican state Sen. Becky Skillman of Bedford as his running mate during his successful run for governor in 2004, in part because she was a woman. She did overshadow him on the day he announced his decision and made public appearances with him.

But the limelight quickly moved back to him. There weren’t many Daniels-Skillman bumper stickers or buttons around during the campaign. Most of those read “My Man Mitch.”

Running mates can bring attributes that can help the ticket in the election — at least somewhat — and prove valuable as a lieutenant governor partner to the person elected governor.

The lieutenant governor in Indiana is not a token post. Although they preside over the Senate in mostly a ceremonial role, they can break tie votes. They used to oversee the Department of Commerce in leading the state’s economic development efforts.

A new quasi-government agency has that role now, and Daniels serves as its board chairman. But the lieutenant governor’s office still oversees several departments, including agriculture, rural affairs, tourism, and housing and community development.

When Frank O’Bannon dropped his gubernatorial bid and became running mate to a much younger Evan Bayh in 1988, he brought his southern Indiana ties to the ticket, his older age and 18 years as a state senator.

When O’Bannon successfully ran for governor in 1996, he chose South Bend Mayor Joe Kernan as his running mate. Kernan brought northern Indiana to the ticket, local government experience and credentials as a former businessman.

When Kernan became governor after O’Bannon died in 2003, he nominated Kathy Davis for lieutenant governor. She was city controller for Indianapolis, but also was a former state budget director who worked well with both parties. When lawmakers unanimously confirmed the nomination, she became the state’s first female lieutenant governor.

Skillman brought the Daniels ticket someone from southern Indiana, gender balance, local government experience and 12 years as a Republican state senator with a reputation as a consensus builder.

It was no surprise that this year’s Democratic gubernatorial nominee, Jill Long Thompson, chose someone from southern Indiana — state Rep. Dennie Oxley of the town of English — as her running mate. She won only six counties south of Interstate 70 in her primary victory over Jim Schellinger.

If they are elected, Oxley would bring state legislative experience to the office and close ties with the House Democratic leadership.

But will Oxley as a running mate be a big factor in people voting for Long Thompson? Again, probably not.

William Blomquist, a political science professor at Indiana University-Purdue University at Indianapolis, noted that Indiana use to elect a governor and a lieutenant governor separately. He said on one occasion it resulted in the state’s two top officials being from different parties.

Blomquist said the state constitution was amended in the early 1970s to put the two posts on the same ticket, both to prevent that scenario and because voters generally knew little about lieutenant governor candidates.

“It reinforced the point that people are picking a governor, and the lieutenant governor comes along in tow,” he said.