Today’s the day.

The preparation, the news conference and the political fights will culminate today as the defenders of Maine’s three military bases slated for closure or consolidation make their case before the Base Realignment and Closure Commission.

There’s reason to be hopeful. And reason to be concerned.

Information on the BRAC Web site suggests that the commission is taking a second look at Pearl Harbor, the naval shipyard most directly competing with Portsmouth Naval Shipyard for survival. It’s a welcome indication that BRAC is keeping its pledge to review the Pentagon’s recommendations.

But the commission also raises serious questions about the realignment of Brunswick Naval Air Station. Savings, according to the document, would be greatly increased if the base were closed, not just downsized.

Maine has rallied for the three installations. Political leaders have effectively made a public case for keeping the facilities open. Today in Boston, they’ll get one more chance to convince the commission before it delivers a final list to the president and Congress in September. The BRAC recommendation can’t be amended. It must be approved or rejected in its entirety.

Much is at stake for the state and the country. The governor’s office estimates that as many as 12,000 jobs could be affected by the proposed base closings and the realignment, delivering an economic shock of $465 million to an already fragile fiscal outlook.

During past rounds of base closings, the commission has OK’d about 85 percent of the Pentagon’s recommendations. Maine’s congressional delegation has developed a convincing argument for why the state’s three facilities are important to national defense, make economic sense for the military and are vital to their host communities.

We hope, the commissioners will be listening.