It’s do-or-die time for the city of Madison.

Tomorrow, a private investment of about $80 million will come in front of the City Council. If 14 alders vote yes, the plan has a fighting chance of becoming a reality. If not, the plan is dead.

Two weeks ago, Landmarks Commission ruled that the building was visually incompatible with the Mansion Hill neighborhood and, therefore, refused to award a certificate of appropriateness or grant the developers variance. In English, that means they thought it was too tall and didn’t fit with the buildings around it.

The redevelopment of the Edgewater Hotel is worthy of the city’s support for three reasons.

First, the revised plan under consideration from Hammes Company represents a fair compromise between a handful of disgruntled residents and Hammes, and there are few reasonable concerns left among the opposition. The idea that this building is not visually compatible is based on the principle of historic preservation, something the height of this project alone will not threaten.

Second, this is the largest project facing Madison since Monona Terrace — a public venture that took years to gain approval. If the city cannot find a way to pass a private project of this magnitude without dictating dimensions, it will only reinforce the old adage that you can’t do business in Madison.

Third, and perhaps most obvious, this is a huge amount of money that will create hundreds of jobs both during and after construction and is fully worthy of the requested $16 million in tax increment financing due to the increase in property values it will produce in the area.

This process has been very frustrating to watch. Despite several missteps by the developer, objections based on the building’s height are among the pettiest concerns raised by opponents. The first plan, which Hammes scrapped earlier this year, was a bit more ambitious than the current proposal. That 12-story tower was significantly higher than anything in the area and took away views of the lake. We understood these concerns but still believed the plan was important enough to warrant our support.

Since then, Hammes has sensibly scaled the project down — to the exact height of the National Guardian Life Building on Gilman and Wisconsin. The company did this even though it meant lower profits, mainly because it wanted to work with the Mansion Hill Steering Committee and prominent resident Fred Mohs.

Mr. Mohs and the committee have given Hammes no credit for these changes, still claiming the building is too tall without giving any discernable reason as to why they think that — forcing us to conclude the committee members have ulterior motives for opposing the hotel.

Hammes President Bob Dunn has said reducing the scale of the building any further is economically unfeasible, so a vote of no from the council tonight will doom the plan.

Madison’s alders: quit worrying about the language of one unclear ordinance. The building fits the neighborhood, will create hundreds of jobs and its failure would mark a sad day for the city’s relationship with business.

And to the thousands of students and downtown residents who we know support this plan, let the council know through e-mail. Better yet, go to its meeting tomorrow at 6:30 p.m. in Room 201 of the City-County Building, 210 Martin Luther King Jr. Blvd.