March for America: illegal immigration rally, March 21, 2010 Washington DC
On March 21, 2010, yet another pro-illegal immigration march will be held in Washington DC, this sponsored ultimately by the far-left National Council of Churches . The next day they'll apparently be conducting a lobbying effort, sending attendees to speak to their representatives (presumably illegal aliens will take a pass on that event).
The march is associated with Ecumenical Advocacy Days, a mini-convention focusing this year on the topic of "Migration". One of the speakers will be Frank Sharry. More on EAD at advocacydays.org/about, and more on the march as it develops.
Other groups involved include:
* the Mexican government-linked Illinois Coalition for Immigrant and Refugee Rights 
* the Border Action Network (link)
* the US Conference of Catholic Bishops' "Justice for Immigrants" campaign (justiceforimmigrants.org/whats-new.html)
* breakingbreadwithfamilies.org / changetakesfaith.org
If anyone can find other questionable groups involved please leave a comment.
3/16/10 UPDATE: From this:
Organized by the Center for Community Change (CCC), the March 21 event will be the largest protest march since President Barack Obama took office. It will include activist groups from nearly every state, and revives the labor-religious-community coalition that built the mass marches of 2006.
According to lead CCC March organizer Gabe Gonzalez, SEIU, UNITE HERE, LIUNA and the UFCW have all committed to mobilize for the march. Gonzalez also told me "the churches are totally on board," with evangelical churches--- which have seen a steady rise in Latinos---playing a larger role than in 2006. Such faith-based activist networks as Gamaliel, PICO and the IAF are also involved, which means that a large cadre of very experienced organizers is involved in ensuring the event's success.
...Following the march, activists plan to turn out in large numbers to the Town Hall meetings that congress members will hold during the two week recess starting March 29. The traditional media gave massive coverage to Tea Party members attending town halls last August, and should be under pressure to provide something close to that coverage for the immigrant rights activism at these upcoming events.
On April 10, there will be an immigrant rights rally in Las Vegas with Senator Reid. Reid knows his re-election depends on massive Latino turnout in November, and immigrant rights advocates are sending a message that they will mobilize for him provided he provides leadership on legalization.