On Sunday, Boston's St. Patrick's Day parade went on without the presence of Marty Walsh, the city's new mayor. On Monday, in New York City, Bill de Blasio will be similarly absent. Their absences are the consequences of a long-running debate over the inclusion of gay participants.

The Boston parade, a city tradition since 1901, was boycotted by Walsh this year after negotiations to allow LGBT members to march broke down. Parade organizers don't directly ban gay participants, but they are prohibited from identifying as such. Parade organizers say that homosexuality goes against their Roman Catholic heritage. A 1995 Supreme Court ruling supported the private organization's right to determine who can and cannot march.

"As mayor of the city of Boston, I have to do my best to ensure that all Bostonians are free to participate fully in the civic life of our city," Walsh said in a statement. "Unfortunately, this year, the parties were not able to come to an understanding that would have made that possible."

New York City has a parallel history of gay rights groups fighting for inclusion for decades with no such success yet. Mayor Bill de Blasio will be skipping out on his city's parade for similar reasons, although he did march in an all-inclusive St. Pat's Parade in Queens over the weekend.

Aside from political denunciation, parade organizers in both cities are also starting to feel the pressure from the holiday's other unofficial sponsors: beer breweries. The Boston Beer Company, which makes Samuel Adams, pulled out of the Boston parade last week, and Guiness has pulled its sponsorship of New York City's.