Republican officials in Indiana and Washington expect former Sen. Dan Coats (R) to win a Senate primary next week, setting up an intriguingly competitive November contest with Rep. Brad Ellsworth (D) that will pit two candidates with contrasting backgrounds at different stages in their political careers.

Though both candidates have major strengths ­— Coats, 66, is a respected former officeholder and Ellsworth, 51, is a telegenic former sheriff — the election will measure how well they overcome their political liabilities.

Coats’ post-Senate background as a corporate lobbyist and his long absence from everyday Indiana life are hurdles he’ll have to surmount. After two terms representing Southwest Indiana’s 8th district, Ellsworth will have to defend his votes for the controversial new health care law and other priorities of the Democratic majority in a Republican-leaning state and in a pro-Republican environment.

If he defeats former Rep. John Hostettler, state Sen. Marlin Stutzman and two lesser-known Republicans on May 4, Coats would begin the six-month general election campaign as an early favorite, according to Democratic and Republican strategists and early polling. A Rasmussen Reports poll taken April 13-14 gave Coats a 54 percent to 33 percent lead over Ellsworth.

Democrats attribute Ellsworth’s early deficit to a lack of statewide name recognition and to his late start, after the surprise retirement by Sen. Evan Bayh (D) in mid-February. But they express confidence Ellsworth will be able to close the gap.

“Because we started a little bit later than the other candidates, folks are still getting to know Brad,” said Liz Farrar, a spokeswoman for Ellsworth’s campaign. “Obviously, he’s very well-known and well-liked in the 8th district, which probably tends to be more conservative than the state as a whole. What we believe is that as folks get to know Brad and learn about his background … they like him.”

“While Coats would have to begin the race — assuming he wins the nomination — as the favorite, I think this is one of those races that is likely to go down to the wire,” said Chris Sautter, a Democratic consultant from Indiana.

GOP officials say one of their strongest cards in the general election is Ellsworth’s voting record — something he didn’t have in 2006, when he beat Hostettler in the first of his two landslide elections. They say Ellsworth’s votes for the economic stimulus package, as well as a health care bill that more than 60 percent of Hoosiers say they want repealed, reveal the Congressman to be more liberal than he has let on.

“He’s not the conservative that he tried to introduce himself as in the 8th district in 2006,” said Trevor Foughty, the communications director for the Indiana Republican Party. “I think that’s obviously going to be one of our main themes in the general election.”

Republicans also say Ellsworth has been disingenuous in his opposition to further “bailouts” of Wall Street. They point to his vote in October 2008 for a $700 billion program to stabilize the financial markets.

Democrats counter that Coats will be in no position to criticize Ellsworth on curbing Wall Street excesses. The Democratic Senatorial Campaign Committee has brandished Coats’ lobbying work for Bank of America, which received bailout money, as an example of him being a “Washington, D.C., insider.” Democrats also have noted that Coats hasn’t yet filed a personal disclosure form detailing the sources of his income.

Both Coats and Ellsworth will be emphasizing the more right-leaning aspects of their voting record.

“Hoosiers know who I am; I have served them,” Coats said at a GOP Senate debate on April 20. “I am a Ronald Reagan conservative. I’m for lower taxes. I’m for less spending. I’m for limited government. I’m for personal liberty. Faith, freedom and family have been my guiding lights.”

Ellsworth has bucked his party leadership more frequently than most Democrats. According to a Congressional Quarterly study of House votes in 2009, Ellsworth sided with his party 78 percent of the time on votes that pitted most Democrats against most Republicans — a “party unity” score that was the 15th-lowest among Democrats. He opposes abortion and voted against a party-backed cap-and-trade climate change bill.

“He really does have the ability to appeal to independents and Republicans as well as Democrats,” Farrar said.

Ellsworth actually can boast a more conservative record on gun owners’ rights than Coats, who voted nearly two decades ago for a ban on some semiautomatic assault-style weapons as well as the Brady law that mandated a five-day waiting period for handgun purchases.

In an early warning sign for Coats, the National Rifle Association has already distributed mailers criticizing his votes on gun issues. Coats said at the GOP debate that he is a supporter of the Second Amendment and would not support any additional restrictions on gun ownership.