INDIANAPOLIS -- Former Sen. Dan Coats won the Republican nomination for a U.S. Senate seat in the midwestern state of Indiana Tuesday, in a primary election contest seen as a test of strength for the grassroots conservative tea party movement against the party establishment.
Voters in North Carolina and Ohio also made their choices in House and Senate primaries.
Republican leaders recruited Coats in hopes he could capture a seat now held by retiring centrist Democratic Sen. Evan Bayh.
Coats overcame spirited challenges from four other candidates, including state Sen. Marlin Stutzman, a tea party favorite, and former Rep. John Hostettler, who had the support of onetime presidential candidate Rep. Ron Paul, a libertarian-leaning Republican.
Coats, 66, retired from the Senate in 1998. He has worked as a lobbyist and was U.S. ambassador to Germany under President George W. Bush.
Coats is one of several prominent Republican candidates nationwide denounced by tea party activists as Washington insiders. The Indiana primary was seen as an indication about whether the widely publicized anti-tax movement could have an impact at the ballot box.
But turnout was exceptionally light in Indiana, Ohio and North Carolina, a possible indication that the anger fueling voters across the country over economic woes, persistently high unemployment and Congress itself wasn't translating into votes -- and, perhaps, the limited influence of the conservatives and libertarians who make up the fledgling tea party coalition.
In all three states, candidates backed by Democratic and Republican leaders in Washington squared off against challengers drawing their support from elsewhere. While it's difficult to draw concrete conclusions about the state of the country from just a few races, the results gave some idea of whether the national parties still can influence rank-and-file supporters.
Republicans are expected to score large gains in both chambers of Congress in November's national elections. But their prospects could be hurt if the party is divided between supporters of mainstream Republicans, like Coats, and tea party activists.
Longtime Senator John McCain, the party's 2008 presidential nominee, appears to be shifting more to the right as he faces a more conservative challenger in the primary for his seat in Arizona. Florida Gov. Charlie Crist has avoided a primary showdown against tea party favorite Marco Rubio, opting to run as an independent in November.
In one notable House race in Indiana, 14-term Republican Rep. Dan Burton -- Indiana's longest-serving congressman -- struggled but managed to fend off six primary challengers for his 5th Congressional District seat.
At the very least, the outcome of Tuesday's primaries -- the first set of contests in the two months since Texas held its February primary -- set the stage for November's congressional matchups and provided early insights about voter attitudes ahead of this fall's elections.
In North Carolina, six Democrats were competing in the Democratic primary for the chance to challenge first-term Republican Sen. Richard Burr, whose public approval numbers are lower than expected. Still, Burr easily won his party's nomination.
But the Democratic results were so close that a June 22 runoff is certain between Secretary of State Elaine Marshall and Cal Cunningham, a former state senator who was the favored choice of the Democratic Senatorial Campaign Committee. Neither candidate achieved the 40 percent of the vote needed to avoid a two-person runoff.
In Ohio, Lt. Gov. Lee Fisher, a former Ohio attorney general backed by Democrats in Washington, beat Secretary of State Jennifer Brunner for the Democratic nomination to fill the Senate seat of retiring Republican George Voinovich. Fisher will face former Rep. Rob Portman, the budget director and trade representative under George W. Bush.
Meanwhile, President Barack Obama is urging Hawaii voters to support a Democrat in this month's special congressional election in the urban Honolulu district where he was born.
Obama's 40-second recorded telephone message was expected to be released Tuesday by the Democratic Congressional Campaign Committee.
Obama says he needs a Democrat to support his agenda of holding Wall Street and special interests accountable. He tells Honolulu voters to fill out their mail-in ballots and send them back immediately.
The winner will fill the remainder of the term of U.S. Rep. Neil Abercrombie, who resigned to run for governor.