INDIANAPOLIS (AP) — Democratic presidential hopefuls are wooing Indiana voters with rallies, town hall meetings and TV commercials. But Sens. Hillary Rodham Clinton and Barack Obama are also battling behind the scenes for the support of Hoosier "superdelegates."

Indiana has 13 superdelegates — lawmakers and party officials who are free to vote as they wish at the Democratic convention — plus 72 pledged delegates determined by the May 6 primary.

Superdelegates could determine who gets the nomination in the tight Democratic race.

Indiana's five Democratic congressmen are superdelegates, and all remain undecided. Some are waiting until after the primary to see who voters choose, while others may be hoping for an Obama or Clinton visit to their district.

"They're waiting to see how the candidates conduct themselves, not only in the state as a whole but within the individual districts," said Robert Schmuhl, professor of American studies at the University of Notre Dame. "I think they want to get a sense of the way the wind is blowing in their districts before they would make a final decision."

Rep. Brad Ellsworth, who represents southwestern Indiana's 8th Congressional District, said he wants voters to choose the nominee.

"Eighth District Hoosiers are independent thinkers who will make up their own minds about who they want to lead our country," Ellsworth said. "If it comes down to the National Convention, I am inclined to support the Democratic candidate the voters choose."

Rep. Joe Donnelly, in northern Indiana's 2nd District, said he will wait until after the primary to choose a candidate. He said many factors will play into his decision, such as who can lead the country, expand the vote and deal with issues important to Indiana. The primary vote is also part of the equation, he said.

"It's not an exact science," Donnelly said. "It's a feeling of who can best serve our country."

Visits to Indiana's congressional districts could become more frequent as the state's primary nears. Obama has been to Plainfield, while Clinton has been to Anderson, Terre Haute, Evansville, Mishawaka, Hammond, Fort Wayne, Muncie, Indianapolis and New Albany. Indiana's newest superdelegate — newly elected Congressman Andre Carson of Indianapolis — has attended events for both Obama and Clinton.

Campaigns also court superdelegates with phone calls, which can pay off when it comes time for candidates to make their decision.

Superdelegate Connie Thurman, a Democratic National Committee member from Indianapolis, said her top concerns were health care and NAFTA. Obama called her four times to discuss the issues, she said, but the Clinton campaign called only after she decided to support Obama.

"I had good conversations with him," she said. "What he had to say satisfied my concerns."

Other superdelegates made up their minds earlier.

State Democratic Party Chairman Dan Parker is supporting Clinton, while vice chairwoman Cordelia Lewis-Burks supports Obama. Lewis-Burks supports Obama because of the way he brings people together. Parker said he likes Clinton's experience.

"I wish we could all be on the same page, but we're not," Lewis-Burks said. "Everybody has their reasons."

Obama leads Clinton among delegates whose votes were determined by primaries or caucuses, 1,406 to 1,249. But neither is on track to win enough pledged delegates in primaries and caucuses to clinch the nomination — 2,024 are needed — so the superdelegates could decide the outcome.

Clinton leads among superdelegates who have announced a choice, 250 to 213. But about 41 percent of superdelegates are undecided or have not yet been named by the party.