Griffo noted that opponents of a project can register their opinions through their representatives in Congress. However, two of Maryland's most influential members, Sen. Benjamin L. Cardin and Rep. Elijah E. Cummings, are outspoken Red Line backers.
Cummings, in particular, could play a pivotal role because of his standing in the African-American community. At the public gathering in Baltimore where O'Malley announced his decision, Cummings forcefully rebuked jeering opponents and rejected suggestions that the state go back to the drawing board.
"This is a once-in-a-lifetime opportunity." Cummings said. "The stars have aligned."
Opponents could throw those stars out of alignment if they are able to demonstrate flaws in the process the state followed or in the numbers underlying its valuation of the project.
Red Line critics are preparing to do just that. The Transit Action Council of Metropolitan Baltimore, for instance, is expected to raise objections that the MTA never did a complete analysis of heavy rail such as the existing Metro subway as a potential option. The MTA will dispute that, arguing that it looked into heavy rail and determined that it would be too expensive to warrant a full-blown study.
Other opponents are already focusing on revisions the MTA made to its ridership projections. The opposition blog Red Line Underground last week demanded that the MTA explain how that estimate could have increased 28 percent - from 42,190 to 54,000. It's a question the FTA could pose, too.
But Henry Kay, the MTA's deputy administrator for planning, said the new numbers will come as no surprise to the federal agency. The state and federal agencies have worked closely each step of the way, and formulas used to reach the new projection - using 2007 data rather than 1996 numbers - have been thoroughly vetted, he said.
"I'm comfortable the work will stand up to FTA scrutiny," he said.
If the federal agency finds no serious MTA errors and approves the project, the focus of the battle could shift to funding. Even if the Red Line receives full federal funding, the state would likely have to come up with at least $800 million toward its share, and foes could seek to derail the project in Annapolis.
While transportation projects are not part of the general appropriations process, the opinion of local legislators can be decisive when officials set priorities.
"They're not going to do it over the objections of the local delegations," Kay said.
