Pat Tiberi ignited a free-for-all last fall when he said he would resign his seat in Congress. https://t.co/orU6jqtw3l

— Enquirer (@Enquirer) April 28, 2018

The 12th District, shaped like an elongated letter C, runs from Mansfield to the northern Columbus suburbs, then stretches eastward to Zanesville and southern Muskingum County. The district long has been represented by a certain kind of Republican. Before he became governor, John Kasich won the seat in 1982, then passed it in 2001 to Tiberi, who had worked in Kasich’s office.

Tiberi’s retirement to run a lobbying group of Ohio CEOs leaves an opening to rebrand the district. Will it continue to be represented by moderate, establishment Republicans, or will it trend toward grassroots conservatives? Will Democrats find a candidate who can galvanize moderate Republicans and Trump opponents and try to turn the district blue for the first time since the early 1980s?

Anything could happen, experts say. Cook Political Report, a leading source of analysis on congressional races, on Friday labeled the district a “toss-up.”. The race is likely to attract national attention and spending as Democrats seek to take control of Congress.

Eighteen Republicans and Democrats are vying for the seat. Most are running both to finish Tiberi’s term this year and to win the seat for the 2019-2020 term. The primary for both races is May 8. The top Republican and the top Democrat will face off Aug. 7 for the rest of Tiberi’s term and Nov. 6 for the 2019-2020 term.