WASHINGTON (AP) — At a recent gathering of House committee and subcommittee chairmen, Republican lawmakers were asked if they could name the legislative affairs staffer at the White House responsible for staying in contact with their panel.

Not a single one could, said Rep. Greg Walden, who heads the House Republicans' campaign arm.

"I shared this story with a Democratic colleague the other night," Walden said in an interview. "He said, 'We face the same problem.'"

If President Barack Obama's dinners and lunches and his unprecedented three days of visits to Capitol Hill stand any chance of bearing fruit, it will be up to him to put the entire force of his White House operation behind opening lines of communication with Congress.

It's a task that many lawmakers say has not always been a top priority for the White House.

Democrats and Republicans on Capitol Hill say that while Obama's new outreach — his so-called charm offensive — is a welcome step, it's the daily contact with White House aides that will ultimately foster greater trust and coordination between the executive and legislative branches.

"It's been spotty," Sen. Bernie Sanders, I-Vt., who chairs the Senate's Veterans Affairs Committee. "It's been up and down. I think there was a period where it was pretty good. I think there was period when it was pretty bad."

Republican Sen. Lamar Alexander of Tennessee, who last week received a call from Obama, said he otherwise has had little contact with White House officials.

"It's an odd way to do business," he said.

White House officials promise a shift, a second-term strategy designed to capitalize on openings for bipartisan legislation that didn't present themselves in Obama's first four years. White House chief of staff Denis McDonough, for instance, has been among the White House officials following up with Republican senators who dined with Obama last week.

"In second terms you have different dynamics and different opportunities," White House communications director Jennifer Palmieri said. "What we see now is a chance for there to be bipartisan support on a number of issues — immigration, guns, fiscal issues. A year ago, it wasn't clear you would have the opportunity to do that."

While Obama may not have deep congressional relationships, many on his staff do. His senior counselor, Pete Rouse, was called the 101st senator when he worked for a former Senate Democratic leader, Tom Daschle. Senior adviser Valerie Jarrett is on a first-name basis with an array of lawmakers. Rob Nabors, the deputy chief of staff and former head of White House legislative affairs, was a staff director on the House Appropriations Committee.

"You would think that the ability to follow up and stay engaged ... should work well," said former Obama chief of staff William Daley. "They have the people that can do that, if they are deployed."

Daley noted that during Obama's first term, the last major piece of legislation that had to be shepherded through Congress was a massive financial regulatory bill in 2010.

"That's almost three years ago," Daley noted. "So what's the point of hanging around up there when nothing's happening?"

Several Democratic senators interviewed say they have personal relations with Rouse or Nabors and feel they can call them any time. But other lawmakers, particularly Republicans, believe such contacts have been sporadic.

Obama raised eyebrows among congressional Democrats and Republicans earlier this year when he promoted Nabors, a well-known figure in the Capitol, and replaced him with Miguel Rodriguez, a former aide to Hillary Rodham Clinton who followed her from the Senate to the State Department. Many in the House and Senate, including in leadership offices, are unfamiliar with Rodriguez. Even Daley, who served as White House chief of staff throughout 2011, said he didn't know the new top legislative aide.

Rodriguez is highly regarded in the White House, officials there say. Sean Kennedy, who knows Rodriguez from when he served as special assistant to Obama for legislative affairs during the first half of Obama's first term, said Rodriguez is tactical as well as substantial. He said that even though Rodriguez may not have Nabors' name recognition, Rodriguez would gain that by the end of Obama's term.

Republicans also complain that the White House has not shown much regard for the institution. They point to the evening in November when Obama held a screening of the movie "Lincoln." None of the invited Republicans showed up. Democrats saw that as a snub of the president; Republicans characterized it as lack of consideration for the Senate schedule.

Alexander said his staff received an email from the White House on a Monday asking whether Alexander was available to watch the film on Thursday evening. But Thursdays are typically days when many senators head back to their states for long weekends.

"My staff emailed back, 'the senator will be in Tennessee Thursday night,'" Alexander said. "Next thing I know the White House staff put out something that made it look like I'd been discourteous to a presidential invitation. I didn't consider that a presidential invitation. It wasn't from the president. It didn't mention the president; it didn't say the president would be at the movie."

Such tensions between a White House and Congress are institutional, and a president's legislative team has to balance the president's agenda with the agendas of 535 members of Congress.

Kennedy, the former White House official, recalled a conversation with a Democratic senator who was resisting an element of Obama's agenda. The senator ended the discussion by calmly telling Kennedy: "Sean, presidents come and go, but the Senate is forever."

"The message is, 'I'm going to be here when Barack Obama leaves office, even if he's re-elected. And you can say what the president's agenda is, but you also need to be very mindful of what my agenda is,'" Kennedy said. "A, that's accurate and, B, the White House gets that."