INDIANAPOLIS (AP) -- Former Sen. Dan Coats won the Republican nomination for Indiana's open U.S. Senate seat on Tuesday, moving closer to a political comeback after being out of office for 12 years.
Coats beat four other Republicans during Indiana's primary election -- including state Sen. Marlin Stutzman and former Rep. John Hostettler -- to win the GOP nomination for the seat being vacated by Democrat Evan Bayh.
But Coats only won about 40 percent of the vote with 71 percent of precincts reporting, signaling a divide in the GOP between mainstream Republicans and more conservative tea party voters who split their votes between Hostettler and Stutzman.
That divide could be an issue in November when Coats will face Rep. Brad Ellsworth, a conservative Democrat who will be formally nominated by the Democratic central committee May 15.
"Ellsworth has enough conservative credentials to cut into some of the Republican base," said Brian Vargus, a political science professor at Indiana University-Purdue University at Indianapolis. "It is completely possible that those people who are disaffected from the party -- the so-called tea party voters -- vote Libertarian or stay home."
Coats, backed by national GOP leaders during the primary, hopes to convince tea party voters that he echoes their concerns about where the country is headed under Democratic leadership.
"We're going to be singing off the same song sheet between now and November," said Coats spokesman Pete Seat.
Diane Hubbard, an active member of the Indianapolis Tea Party group, said it's hard to say whether tea party voters would support Coats, vote Libertarian or stay home in November.
"I don't think they're going to be excited about Coats, but they very well may vote for Coats," Hubbard said. "We hope people will get out and vote for the most conservative candidate."
Coats won a special election in 1990 to serve the remainder of Dan Quayle's term after Quayle became vice president in 1989. Coats' name was last on an Indiana ballot in 1992, when he made a successful bid for a full Senate term.
But he decided not to run for re-election in 1998, when Bayh made his first run for the seat. Coats has since been an ambassador to Germany under former President George W. Bush and worked as a lobbyist in Washington.
Democrats wasted no time Tuesday in attacking Coats.
"National Republicans got who they wanted, and who they got is an establishment Republican steeped in the culture of Washington. A super-lobbyist beholden to special interests for his fortune," Democratic National Committee Press Secretary Hari Sevugan said in a statement. "Dan Coats may represent national Republicans to a tee, but he doesn't represent the values of Hoosiers anymore."
But Republicans were equally quick with their criticism. Indiana Republican Party Chairman Murray Clark said Ellsworth was nominated by the Democratic Party's 32-member state central committee instead of going through the primary election process.
The timing of Bayh's announcement left no time for a Democratic Party candidate to submit enough signatures by the filing deadline.
"While Rep. Brad Ellsworth has shown time and again that he's influenced more by the status and power of his Democrat party bosses and the 32 party insiders who will anoint him in 11 days, Dan Coats earned the nomination through a process in which hundreds of thousands of Hoosiers participated," Clark said.