What is the Washington National Cathedral doing involved in such obviously political causes?: Pushing for Gun Control

Why is the National Cathedral taking political stands?

The Very Rev. Gary Hall is dean of the Washington National Cathedral in Washington, D.C. . . . 
In partnership with the Newtown Foundation, the National Cathedral is holding a national vigil on December 12 to honor the lives lost at Newtown and the more than 30,000 Americans who have died from gun violence this year. . . .

The National Cathedral has gotten some money from the federal government, but obtains other benefits simply by being labeled as the "National Cathedral."  I have no problem with churches getting involved in whatever political issues that they want.  The question is whether the National Cathedral is something different.  

From the Washington Post:

The annual "Save America's Treasures" grants were announced Tuesday at a ceremony at the historic President Lincoln's Cottage in Washington, D.C. A coalition of organizations, led by the National Park Service, the President's Committee on the Arts and the Humanities and the private National Trust for Historic Preservation presented $14.3 million to the groups. 

The Washington National Cathedral, the towering center for worship and important national services, received $700,000 for repairs that any large building constantly needs. "The building is over 100 years old in some places and one of the principal needs is repointing. The mortar deteriorates over time in each of the limestone blocks," said Andrew Hullinger, the cathedral's senior director for finance and administration. And even sacred places have the same to-do list as ordinary homes, said Hullinger, citing foundation leaks and repairs to underground and interior drain lines. "The need ranges from nuts and bolts to art preservation." . . . .