Coats, R-Indiana, said in an interview with ABC News that his opponent for the Senate seat, Democratic Rep. Brad Ellsworth, is the real insider in the race.
"Right now, he is," Coats said. "I'm a candidate running for office. Brad Ellsworth is an incumbent sitting in office. People are unhappy with what's happening in Washington under this administration. He was there; I wasn't."
Coats' attempt to return to Congress, after more than a decade out of office, marks something of a test case for how voters' anger is being directed this year.
Coats has the resume of the consummate insider Democrats contend that he still is. He served 20 years in the House and Senate and took an ambassador's post under President George W. Bush, before making millions as a Washington lobbyist.
The "insider" tag dogged him through the GOP primary. Coats last week prevailed over a tea party favorite, State Sen. Marlin Stutzman, and a former House member, John Hostettler, in a campaign in which his lobbying ties where a major issue.
Now, Indiana Republicans are rallying behind Coats in the hope that he can win the seat held by the retiring Democratic Sen. Evan Bayh.
Coats said he's stronger for the experience of having been through a primary -- and grateful that he's not seeking another Senate term from the perch of the U.S. Senate.
"Had I been an incumbent, I think it would have been a different -- probably a different story" in the primary, Coats said. "People were more willing to say, 'Well, he wasn't part of that.' I was able to share that I was just as disillusioned with some of the things as they were."
Democrats contend that Coats won't be able to shed the baggage he accumulated inside the Beltway.
"The only thing he's an outsider to in this race is Indiana, since he didn't even have a residence in Indiana until he decided he would run for the U.S. Senate," said Adam Elkington, a spokesman for the Indiana Democratic Party.
"Hoosiers have a clear choice in this race for Senate: a Washington, D.C., lobbyist who represents Wall Street banks, foreign nations and corporations that ship Hoosier jobs overseas, or a former sheriff from Evansville, Indiana, who will represent Hoosier families."
Democrats have hammered Coats over his lobbying for, among other clients, major Wall Street interests. His firm has done work for Merrill Lynch, Goldman Sachs, Bank of America, and the New York Stock Exchange.
Coats said Democrats are misconstruing his lobbying work. He promised to make public as many details as possible about his work -- "everything anybody wants to know" -- in the coming days, though he acknowledged some difficulties in disclosure owing to attorney-client privilege.
"I'm willing to sit down and explain it," Coats said. "The problem is attorney-client relationship. So it's a dilemma in the sense that you can't -- you're not in a position to disclose the positive in any kind of detail of what you did for them, but you're vulnerable to whatever the negative for whatever they say that it was."
Coats said he hasn't been following the day-to-day maneuverings around the financial regulatory reform debate to say for sure how he'd vote. But he expressed concern that Congress would overreact and wind up passing new regulations that would add to consumers' costs.
"Congress legislates all the way to this and drags everybody else into it, and I'm afraid if we're not careful that's what'll happen on financial reform," Coats said.
Coats said he would return to the Senate with a different perspective than he had in his first stint in office, colored in part by his experiences since leaving the Senate.
Coats was tasked by the Bush White House with shepherding Harriet Miers' nomination through the Senate in 2005 -- a doomed quest, with President Bush forced to withdraw her name from consideration amid GOP and Democratic opposition.
Miers, like Elena Kagan now, faced questions about her lack of judicial experience. Coats was placed in the position of defending Miers' "life experience," as opposed to "judicial experience."
He said in the interview that those questions are legitimate -- whether asked of Miers then or of Kagan now.
"I don't think that's a necessarily absolute prerequisite, but it's an important qualification," Coats said, "because it provides a record and it gives people an insight to how they view the Constitution, the role of a judge or a justice, and an insight into whether or not they are a strict constructionist, whether they think it's a living document and all these things. You have a record to match the rhetoric."
"Yeah, it's legitimate, but I'm not saying it's a deal-breaker. But it's one of the important considerations," Coats said.
As for his opponent this fall, Coats cited Ellsworth's support for the health care law as evidence that he's an "enabler" for the Democratic agenda. And though they're vying for the Senate, it's the House speaker on Coats' mind.
"In other words, when push comes to shove, he does what Nancy Pelosi wants him to do," Coats said. "We elect you, we put our trust in you, you go to Washington, and then, for God's sake, you vote for Pelosi."