Two Portland men became the first gay couple to marry in the state
Advocates confident of sweep in Md., Maine, Minn., Wash. battles
Voters in Maine, Md., Minn. and Washington to consider measures next week
Polls indicate majority of voters would support ballot measure to allow same-sex marriage.
The Vermont-based organization claims more than a million members
Campaigns in Maryland, Washington, Minnesota and Maine each received $250,000.
Potential donors in D.C. say Marylanders for Marriage Equality has yet to approach them