Both filed petitions Wednesday in Cleveland to challenge each other in a district that snakes from Toledo to Cleveland.
The representatives were matched against each other by the Republican-dominated Ohio General Assembly, which approved the new congressional district map. As a result of the last census, the state was forced to reduce its number of congressional districts to 16 from 18 because of sluggish population growth over the last decade.
Mr. Kucinich, 65, an eight-term congressman who twice has run for president, announced in September that he would oppose Miss Kaptur, also 65, after Republicans put the two together in a district that hugs the Lake Erie shoreline.
The current map is a compromise reached after complaints from Democrats that the first version was too partisan and split too many counties in half.
The congressional filing deadline was extended this month after the revision of the new congressional map. The new map moved many of Miss Kaptur's prior constituents back into the 9th District, meaning that it has a bigger part of her current district and that the district as a whole could be considered friendlier for her.
Mr. Kucinich declined to comment on that assumption.
"I will leave that for the analysts. I am in this race and obviously I wouldn't be in it unless I thought I could win," he said. "Obviously, the people are going to have affection for someone they've worked with for many years -- that is life -- and so I believe that. … I certainly have to be in a position to let the people of Toledo know they won't be forgotten."
Mr. Kucinich, who ran for president in 2004 and 2008, has a national following among progressives. He has been known for his offbeat, brash style since becoming Cleveland's mayor in 1978 at age 31.
Miss Kaptur is the longest-serving woman in the House. She was first elected in 1982. Labor leaders urged her to run for governor in 2006, but she decided to stay in Congress. She said the new congressional map would aid her re-election effort.
"There are parts of five counties in the district, and I have represented and carried four of them," Miss Kaptur said. "There is a very short time for us to introduce ourselves to the portions that have been added, which is Cuyahoga County."
Miss Kaptur also said while she has represented Lorain County, new areas, including the city of Lorain, have been added to the new 9th District.
"The disadvantage is we have to move into the Cleveland media market, which is quite expensive," she said.
Miss Kaptur said she would not attack Mr. Kucinich during the campaign. Each of the two lawmakers has called the other a friend.
"I am going to be talking about my vision based on the experience I have gained in representing the region," she said. "I am not running against anybody. I am running for the 9th District and taking their concerns to the national level."
Mr. Kucinich promised to open a congressional office in Toledo should he be elected.
"There are those who say that the length of the new district will make serving the people more difficult," Mr. Kucinich said. "To them I say when people need help, we have never asked where they live, we ask only how we may help. The new district should be received as an opportunity to be of service, a blessing."
He touted his record, saying he would work on similar issues if elected.
"In my time in Congress, I have helped save and/or create thousands of jobs in manufacturing, health care, advanced technology, space, and aeronautics," Mr. Kucinich said. "I have worked to help save Ohioans' homes, rebuild neighborhoods, to protect the quality of our air and water, and to preserve Lake Erie as a source of drinking water and recreation. If nominated and re-elected, I intend to continue these efforts and extend them to the new district which reaches out to Lorain and west to Toledo."
Congressional candidates have until Friday to file their petitions to run in the March 6 primary.
Samuel J. Wurzelbacher, also know as "Joe the Plumber" since he burst into national politics during the last presidential campaign, is running in the GOP primary for the 9th District seat. Sandusky auctioneer Steven Kraus also has filed signatures to run in the GOP primary.
The winner in that race would face either Miss Kaptur or Mr. Kucinich.
Contact Ignazio Messina at: email@example.com or 419-724-6171.