WASHINGTON - The Republican state senator who shook the political landscape from Massachusetts to California this week descended on Capitol Hill to a celebrity's welcome Thursday as he to introduced himself to a Congress he says has lost its way.

Sen.-elect Scott Brown acknowledged that winning the seat held since 1962 by the late Sen. Edward M. Kennedy in Tuesday's special election upset presented unique challenges.

"I'm stepping into shoes that are very, very big," Brown said during a meeting in Kennedy's former offices.

Brown made other gestures of humility and substance during visits with Senate veterans and leaders.

"This is the best place in the world when it comes to solving problems," Brown said, "but we've sort of lost our way."

Washington greeted the Cosmopolitan centerfold, followed through the complex by a camera-clicking mob, more like movie idol Brad Pitt - who created a major fuss at the Capitol in March - than Jimmy Stewart's Mr. Smith who went to Washington.

Brown said he was overwhelmed. Inciting a particularly dense swarm after one meeting, he expressed hope "no one trips" in the frenzy.

Republican leaders are hoping the same thing about Brown, largely unknown outside Massachusetts until he began surging past Democrat Martha Coakley to capture the Senate seat held by Kennedys all but a few months since 1953. Welcoming Brown first was Sen. John McCain, the GOP presidential nominee in 2008 whose

independent streak has often riled other Republicans.

Brown, who campaigned emphasizing his independence from either party, recalled that McCain was one of the first people "in this very office, to look me in the eye and say, `Well, you're a longshot, but I'm with you."'

Brown's victory shook President Barack Obama's Democratic Party to its core, breaking its 60-vote Senate majority, jeopardizing health care reform and sending a shudder through even the most well-funded Democratic incumbents up for re-election in November.

"Every state is now in play," said Sen. Barbara Boxer, D-Calif., a campaign chairwoman and one of the Senate's most prolific fundraisers who was suddenly, since Tuesday, considered by some a little more vulnerable for re-election next fall. As the senator-elect behind all the uncertainty got the feel of his new workplace, House Speaker Nancy Pelosi made official more difficult news for Democrats: The Senate-passed health care overhaul did not have support from the 218 House members it needed to become law.

Senate Republican leader Mitch McConnell found a pithy way to describe the place Brown holds in the clubby Senate even before being sworn in. He recalled that on the campaign trail, Brown sometimes signed autographs, "41" - the GOP's 41st vote against the Democrats' health care bill, the magic number required to kill it or anything else on Obama's agenda in Congress.

"I will always think of him as 41," McConnell said.

Despite the unpleasantness Brown presented them, Democrats greeted him politely.

Senate Majority Leader Harry Reid said the two had found at least one thing in common: They both have children who are college athletes.

But those closest to Kennedy were warmer.

They included Kennedy's son Patrick, a representative from Rhode Island, and Sen. John Kerry, the Democrat with whom Brown will steer legislation affecting Massachusetts.

"Scott very successfully managed to tap into anger and impatience that's very, very real. So it's a good lesson," Kerry said.

"I hope Republicans on the other side of the aisle hear it as well."

Later in Kennedy's former office, Paul Kirk, the former Democratic Party chairman who was appointed interim senator after Kennedy's death in August, said Brown had made it clear that he would be an independent voice.

"I heard him loud and clear," Kirk said.

"He's going to be his own man."