Ohio lawmakers are on track to pass a bill that moves the primary to a single March 6 date while tweaking the state’s new Congressional map.

In this redraw, Buckeye State legislators would consolidate precincts in urban areas and shift population around Toledo to benefit Rep. Marcy Kaptur’s (D) re-election.

Democrats and Republicans expect the bill to pass the state Legislature with substantial bipartisan support as “emergency” legislation, which means Democrats will not be able to put the map on the ballot as a referendum.

Democrats protested earlier this year when Republicans drew a new Congressional map intended to give the GOP a 12-to-4 advantage in the delegation. But Democrats struggled to gather enough support to put the map on the 2012 ballot as a referendum, coming up short of the requisite signatures several weeks before the late December deadline.

Republicans didn’t change that overall 12-to-4 advantage under this most recent redraw, but they did make some minor changes aimed at picking up more Democratic support.

Specifically, the revised map shifts about 100,000 voters in the lakeshore 9th district to benefit Kaptur’s bid against Rep. Dennis Kucinich (D) next year, according to a Democratic source.

The map slightly improves the Democratic performance in districts held by GOP Reps. Jim Renacci and Bill Johnson, although the districts still favor Republicans, the same Democratic source said. Local newspapers also reported the new map keeps urban precincts around Columbus, Dayton and Cincinnati more intact than the previous map.

The bill also sets a new filing deadline of Dec. 30 for Congressional and presidential candidates.

The map changes came as a surprise to some Ohio House Members. Rep. Patrick Tiberi (R) appeared to have little advance knowledge of the new map as he looked at a copy on his iPad this afternoon at the Capitol alongside his colleague, Rep. Devin Nunes (R-Calif.).

Tiberi told reporters that he’s heard Ohio Republicans have enough Democratic votes to pass the new map, and a vote will be scheduled soon.

Rep. Steve Chabot (R-Ohio) was delighted with the new map, saying, “My district would be strengthened” to be “much better than it is now.”

Legislators had approved splitting the contests earlier this year, with the Senate primary in March and the House and presidential primary in June. Ohio lawmakers say they will save $15 million by combining the primaries into a single March date.

Richard Cohen and Daniel Newhauser contributed to this report.