In a sign of growing collaboration between Congressional Democrats and their party’s standard-bearer, a top aide to Sen. Barack Obama’s (D-Ill.) presidential campaign met for the first time Wednesday with the entire House Democratic Caucus.

David Plouffe, Obama’s campaign manager, gave a presentation on 18 key battleground states and highlighted how the campaign will lean on its grass-roots supporters, which are estimated at 1.8 million donors and 1 million volunteers.

Plouffe “showed a lot of maps” that highlighted Obama’s strengths and weaknesses, and he talked about how the presidential race is “going to be won on the ground,” said Rep. Jan Schakowsky (D-Ill.), a national co-chairman of the Obama campaign.

Schakowsky noted that Obama appointed longtime House aide Phil Schiliro to serve as the House liaison for the campaign. Schiliro’s role will be to maximize the use of Members to organize in their districts and to serve as national surrogates for the campaign.

House Majority Leader Steny Hoyer (D-Md.) predicted that the Obama campaign will give a boost to Congressional Democrats “in every area.” He praised the campaign for inspiring numbers of volunteers “that are unprecedented in terms of people power.”