With a long and brutal primary finally behind him, Sen. Barack Obama (D-Ill.) is expected to take the next several weeks developing a network of contacts and proxies in the House and Senate to coordinate message and agenda activities, as well as critiques of GOP presidential hopeful Sen. John McCain (Ariz.).

While Obama and Sen. Hillary Rodham Clinton (D-N.Y.) were still competing in the primaries, Senate Majority Leader Harry Reid (D-Nev.) did not prepare an internal coordination strategy, aides said, preferring to wait until a nominee was known to avoid the appearance of favoring one over the other.

“Sen. Reid has studiously avoided doing anything on that,” a Reid aide said, adding that preliminary meetings with Obama’s campaign and internally within the Conference could begin this week.

Presidential candidates typically begin to quickly build communications networks to the two chambers, because they are effective avenues for not only highlighting a candidate’s priorities but also for offering a platform to defend a party’s nominee or attack an opponent.

Democratic strategist and lobbyist Steve Elmendorf, a former top aide to former House Democratic leader Dick Gephardt (Mo.), said it is crucial for Obama to have Hill help, in part because his campaign is based in Chicago, not in Washington.

“I think it’s important that they have a presence here in terms of the House and the Senate,” Elmendorf said. “It takes a load off the people in the headquarters.”

After Gephardt’s unsuccessful 2004 presidential primary campaign, Elmendorf moved to become deputy campaign manager for party nominee Sen. John Kerry’s (D-Mass.) bid.

Without staff liaisons in the House and the Senate to channel information, Elmendorf said, Members will end up calling senior campaign officials directly — in this case chief strategist David Axelrod or campaign manager David Plouffe.

Liaisons are also a linchpin in the day-to-day coordination that needs to happen between Members, leadership on the Hill and the campaign on everything from media events, travel, message and scheduling floor legislation.

Elmendorf said it is important for Obama to have someone whom Members see and then identify with the campaign — someone who can satisfy “the Members’ constant need for information about what’s going and what’s the candidate’s doing.”

But Senate Democratic aides close to the campaign said late last week that given the length of this year’s Democratic primary and that a recess is only a few weeks off, it is unlikely the campaign and Democratic leaders will use the next two weeks to build their communications network.

“I doubt you’ll see much before the recess,” one senior Democratic leadership aide said, adding that one advantage of the protracted primary is that the leadership in both chambers already have a handle on the campaign’s agenda. “We’ve already started doing some of this, like the ‘change’ stuff.”

Additionally, the aide predicted a fairly seamless transition, saying that much of the polling and message development that has been done for Obama’s campaign has also been previously provided to Senate Democrats.

“It’s not like they were getting polling that said this is a change election, and we were getting stuff that said it’s a status quo election,” the aide said.

In the recent past, Democratic presidential contenders have looked to K Street to find their Hill liaisons. Lobbyists, many of whom began their careers on the Hill, serve as a nexus of the money and political worlds inside the Beltway.

In 2004, the Kerry campaign hired lobbyists David Castagnetti and Broderick Johnson, both of whom left lucrative careers on K Street, to be the campaign’s Hill liaisons full time. But that seems unlikely for Obama. Not only has he campaigned against special interest influence, but he also refuses to employ or take money from registered lobbyists.

With K Street viewed as a less likely venue from which to choose liaisons, there are increasing odds that Obama’s campaign will tap Hill aides — and there is plenty of interest.

Whoever is chosen, there is little doubt that Obama Senate Chief of Staff Pete Rouse will play a large role in the selection process. Rouse previously worked for former Senate Democratic Leader Tom Daschle (S.D.).

“Pete Rouse has a unique roll in that he knows more about the Hill than anybody,” Elmendorf said.

Obama is expected over the next several weeks to tap several lawmakers who had backed Clinton’s bid for the nomination to take a prominent role in the campaign, Democrats said.

On the Senate side, Obama could tap either Sens. Charles Schumer (N.Y.) or Patty Murray (Wash.), several Democratic aides predicted. Schumer is a master campaigner and a ferocious fundraiser. Because he is chairman of the Democratic Senatorial Campaign Committee, he could ensure that message and agenda are coordinated downballot.

Murray, who has a good working relationship with Obama, according to one aide, could help heal any wounds felt by female Democratic voters. The same is thought of Sen. Claire McCaskill (Mo.), an early Obama supporter.

Obama also has powerful allies in Majority Whip Dick Durbin (Ill.) and Sen. Edward Kennedy (Mass.), though Kennedy’s health makes his role in the campaign unclear.

In the House, Obama has a handful of allies that are expected to continue to work as proxies for the candidate, as well as act as formal and informal liaisons to the chamber, including Reps. Artur Davis (Ala.) and Illinois Democratic Reps. Jesse Jackson Jr. and Melissa Bean.

Meanwhile, Obama’s vice presidential search committee was on the Hill on Monday meeting with Democratic leaders.

A Democratic aide confirmed that the three-person committee will be meeting with Reid but did not disclose further details. Caroline Kennedy, Sen. Kennedy’s niece, Eric Holder and Jim Johnson sit on Obama’s search group.

The presumptive Democratic nominee has recently voiced opposition to releasing any information on his search for a second-in-command until he makes an official announcement.

Tim Taylor contributed to this report