Ring that bell, because round four officially has begun.

Rep. Baron Hill (D-Ind.) and former Rep. Mike Sodrel (R-Ind.) are facing off in what likely will be their fourth distinctively negative campaign in as many cycles. And with Wednesday marking the first official day of the general election, this cycle is so far proving to be no exception.

“There’s a great personal dislike between the two of them,” said one well-placed Washington, D.C., GOP source, who declined to be named. “I think it’s residual effect from multiple campaigns.”

In 2002, Sodrel challenged and lost to Hill, who was seeking his third term. Sodrel then narrowly defeated Hill in 2004, only to have the Democrat return for round three and win his seat back in 2006.

So what’s different this time around? Republicans point out that the only time Sodrel has won the seat was 2004, a presidential election cycle with record turnout in the state that has voted Republican in White House contests dating back to 1964.

What’s more, this year, Hill has endorsed Sen. Barack Obama (D-Ill.) for president, who lost the 9th district on Tuesday by large margins in most of the counties.

While Obama won Bloomington, Hill’s home base and home to Indiana University, he lost by as much as 50 percent in some of the counties in the district. That’s a fact that makes Sodrel looking forward to having Obama on the top of the ticket, which is looking more and more likely with each passing Democratic primary contest.

“It appears according to the voting results, that Sen. Obama would be better [for me] at the top of the ticket,” Sodrel said this week.

In Scott County, for example, Obama got just 22 percent to 78 percent for Sen. Hillary Rodham Clinton (D-N.Y.).

“They are people that Sen. Obama talked about,” Sodrel said. “They have guns, they go to church on Sunday … they were upset about it. It’s anybody’s guess whether they will have cooled off about it by November.”

Hill stood by his decision to endorse Obama in a statement released by his office Wednesday.

“My decision to endorse Sen. Obama was not a political one, but a decision to publicly support the candidate I believe has the best capability to change the tone and tenor of politics in Washington, end the partisan gridlock and bring people together to move this country in a new direction,” he said “In the end, my focus remains on ensuring Democrats take back the White House in November.”

The southern Indiana Congressional districts, currently both represented by Democrats, are known for voters who split their tickets. It’s not certain that a Democratic presidential candidate could have much of an influence on the voters given their predisposition to vote for both Republicans and Democrats on the ballot.

In fact, the overwhelming feeling in the 9th district might just be that voters are fatigued over seeing Hill and Sodrel wage increasingly negative and expensive campaigns. It’s possible that voters might turn on Sodrel as the candidate who keeps perpetuating the negativity by running for the seat a fourth time.

It’s well-known in Washington that these two men have an extreme dislike for each other. Sodrel conceded that the relationship between him and Hill probably is more unpleasant than most other House candidates in the country.

And as part of the long-term war between the current and former Congressmen, the Democratic Congressional Campaign Committee on Wednesday brought up the previously reported accusation that Sodrel had closed his official office and left casework unfinished when he transferred his constituent services to Hill in 2006.

“The fact that Mike Sodrel selfishly closed his Congressional offices following his defeat in 2006 reveals just how much he cares about serving the people of the 9th district,” DCCC spokesman Doug Thornell said. “He put his own politics ahead of the veterans, seniors and children that were still depending upon his constituent services.”

However, Sodrel’s campaign manager, Ryan Reger, said letters were sent to every open case in the Congressman’s office at the end of 2006 alerting constituents of their status. He added that when Sodrel won the office in 2004, his staff did not receive transferred cases from Hill’s tenure in office.

“If there were supposed to be cases transferred over, then Mr. Sodrel got nothing from Mr. Hill’s office (in 2004),” Reger said.

In the meantime, Republicans are placing their boxing bets on the fact that Indiana will likely vote GOP in a presidential year. The National Republican Congressional Committee pointed out that famed movie boxer Rocky Balboa provides a worthy analogy for round four of the Hill vs. Sodrel fight.

“This is the political equivalent of ‘Rocky IV,’” NRCC spokesman Ken Spain said. “And we believe Mike Sodrel has what it takes to go the distance and pull off a comeback.”