When presumptive Democratic presidential nominee Sen. Barack Obama (Ill.) meets with House Democratic Caucus members today, it will be a key moment in what sources describe as a burgeoning relationship between the campaign and its Congressional allies.

Obama ran against Washington in the primaries, and some Democrats view the session as simply an opportunity for the candidate to reassure lawmakers that he thinks they’re important, sources said.

Sources emphasized that Obama’s support in the Caucus is widespread and genuine. But today’s meeting may not be without contentious moments.

Democrats particularly want to hear from Obama on trade and globalization, sources said — hot-button campaign issues on which Obama has been accused of shifting his views to the right.

Obama is likely to get it from both sides, with Democrats who support less restrictive trade policies pulling from one end and those who want firm guarantees of trade “fairness” pulling from the other.

According to one senior House Democratic aide, fiscal conservatives such as the Blue Dogs have concerns about Obama’s commitment to balancing the budget and plans he may have to use savings from the expiration of the Bush tax cuts for new spending.

Obama aides got some pushback in a recent meeting with Ways and Means Democrats on the issue of tax reform, with some lawmakers insisting on action to end to the alternative minimum tax.

But sources say they believe Obama’s appearance will solidify quiet moves at the staff level designed to increase cooperation.

Democratic leadership press secretaries recently began daily conference calls with the campaign to share intelligence, go over schedules, and make sure everyone is on the same page as messages get pushed out the door.

With the recent appointment of Phil Schiliro as Obama’s liaison to Congressional Democrats, the campaign now has a consistent set of eyes and ears on Capitol Hill. Schiliro, a highly regarded former aide to Rep. Henry Waxman (D-Calif.), now sits in on caucus and leadership meetings, according to a Democratic House leadership aide.

Retinues of Obama advisers, led by Schiliro and policy gurus like Jason Furman, have been making the rounds with various Democratic committee members and other Congressional groups.

Obama is deepening his ties to the Congressional Black Caucus, some of whose members initially backed the candidacy of Sen. Hillary Rodham Clinton (D-N.Y.). Obama met privately with the caucus soon after cementing his status as the presumptive nominee.

Coordination with the CBC will be critical as Obama strives to get out the substantial African American vote in pivotal states like Georgia, Virginia, Ohio, North Carolina, Pennsylvania and elsewhere.

Rep. Elijah Cummings (D-Md.), a former CBC chair and early Obama backer, said caucus members want to hear from Obama that he will continue to forge a close working relationship with them in their districts and make sure the black vote gets out.

“There are a lot of Congressional black caucus districts where, probably, the extra votes will gain him a victory in the state,” said Cummings. Cummings said a well-timed appearance in Cleveland, for example, could push the make-or-break state into Obama’s column.

Rep. Artur Davis (D-Ala.,) another CBC member and one of Obama’s earliest Congressional backers, said discussions between the group and the campaign on getting out the vote are under way.

“The Obama campaign has made clear that it will have an unprecedented voter registration drive,” Davis said.

Davis, who is personally close to Obama, said he expects today’s meeting to include a discussion of some of Obama’s less well known views on topics like Iran, Russia and trouble spots in Africa.

Davis noted that there is probably less need for substantial coordination between House Democrats and their presidential candidate than in previous cycles. Obama became the obvious nominee much later than earlier candidates, and Congress will only be in session for another three and a half weeks, so the block of time available for coordinating activity will be smaller.

But Davis said he expects a second stimulus bill to move in September, and that Democrats will want to solicit Obama’s views on what should be in it.

Sources said Obama plans to discuss his highly publicized trip the Middle East and Europe, which Congressional Democrats believe successfully bolstered his image as a prospective world leader. Iraq is also bound to be on the agenda

Many Members just want to see him and share in the excitement that has gripped Democrats, especially in the wake of his recent voyage.

Today’s meeting is scheduled for 5:30 in the Cannon Caucus Room. Obama is on a tight schedule, according to one source, who said the session will likely last less than an hour, offering perhaps a relatively limited chance for interchange with the entire caucus.