WASHINGTON – Although dozens of Republicans sailed into office with the help of the tea party movement last year, finding a self-identified “Tea Party Republican” on Capitol Hill is harder than you’d think.

The first meeting of the Senate Tea Party Caucus on Thursday attracted just four senators — out of a possible 47 GOP members — willing to describe themselves as members. The event was as notable for who wasn’t there as for who was.

Sen. Marco Rubio, R-Fla., once a tea party darling, has for now declined to join the caucus, whose first meeting was organized by Sen. Rand Paul, R-Ky.

Sen. Ron Johnson, a Wisconsin Republican whose campaign sprang from the small-government movement, has passed for now.

Sen. Pat Toomey, R-Pa., showed up to address the group of activists Thursday, but then hustled out of the room, ignoring reporters’ questions about whether he was in or out.

The reluctance shows how the purposefully disjointed movement and its crop of outspoken and controversial leaders, although a powerful force in a campaign known as the “year of the tea party,” are still viewed as risky allies even for conservative politicians.

With the rhetoric of the campaign now translating into politically painful budget cuts, the tea party agenda looks less like the hub of Republican energy in Congress and more like an endpoint of the spectrum.

To be sure, there are institutional reasons for the Senate Tea Party Caucus’ still-meager membership.

In the House, special interest caucuses serve as a way for like-minded lawmakers to amplify their influence. But in the Senate, which has fewer members, the tactic is less necessary and senators are less eager to join.

The Senate also has a stricter pecking order and more defined set of expectations for new members.

So, it was fairly unusual when, after just a few weeks in office, Paul proposed his own budget. He recommended gutting the Interior and State departments, eliminating the Department of Energy and cutting all funding for public radio and television and the National Endowment for the Arts.

While Paul’s plan cuts $500 billion from the budget in a year — five times what Republican leaders in the House have proposed — it’s not one even some fiscally conservative Republicans have been quick to endorse.

A spokesman for Rubio, a former Florida state lawmaker who edged out Gov. Charlie Crist in a three-way race, said the senator hasn’t read it. Rubio’s own plan for reforming education contains no specific program cuts.

Paul’s approach — bold, specific and unwaveringly conservative — is exactly what the most engaged activists of the tea party have been seeking.

One of the biggest applause lines at Thursday’s meeting came when staunch conservative Sen. Jim DeMint, R-S.C., quoted Paul as saying, “My goal is to make DeMint look like a moderate.”

But it’s not necessarily a pragmatic approach for lawmakers like Rubio or Johnson, who need to attract support from independent and even Democratic voters in their swing states.

Johnson said he was declining for now to join the Tea Party Caucus because it threatened to highlight division among Republicans.

“The reason I ran for the U.S. Senate was to not only stop the Obama agenda but reverse it. I believe our best chance of doing that is to work towards a unified Republican Conference, so that’s where I will put my energy,” Johnson said.

There’s evidence of similar reservations in the House, where many more new Republicans were helped by the tea party.

More than 50 Republicans joined the House Tea Party Caucus in July, during the campaign season. A membership list for the new Congress will be released in February, according to the office of caucus chairwoman Rep. Michele Bachmann, R-Minn.

But several new Republicans have said they’re uncertain whether they’ll join the House Tea Party Caucus, citing worries about demands on their time and an early focus on constituent services.

“I’m amazed at how many different directions I’m being pulled,” said Rep. Steve Southerland, R-Fla. “I represent an incredibly diverse district. There’s a lot of different political persuasions, a lot of different groups. I want to make sure that I represent all of my district, not just one group.”

Others expressed concerns about aligning behind Rep. Michele Bachmann, R-Minn., the caucus founder. Like Paul, Bachmann has sought to stand out as a leader among conservatives in the Congress. However, she has alienated some with her verbal gaffes and tendency to seek out the spotlight.

Her televised response to the State of the Union speech — billed as the tea party response — was met with mixed reviews and criticized as muddling the Republican message.

“Invitations would be viewed more favorably if it were led by someone else,” said one aide to a Republican lawmaker who had tea party support during the campaign. “I think lots of people have their fingers in the air, looking to see where this goes.”

Bachmann and Sen. Mike Lee, R-Utah, who along with Paul, DeMint and Republican Sen. Jerry Moran of Kansas, joined the Senate caucus, have sought to answer such concerns by billing the meetings as listening sessions rather than strategy sessions.

“The word ‘caucus’ is a blunt instrument. I think people think it will be a faction of some sort,” Lee said. “But this is simply a group of senators who are going to hold meetings from time to time with people who agree with the tea party movement.”

On Thursday, some of the grassroots activists expressed frustration with the small number of lawmakers who joined the caucus, as well as with Paul’s budget — which, in their view, did not go far enough.

“I’m disappointed. I wish there were more here, but I’m more disappointed that they haven’t introduced a balanced budget,” said Ken Vaughn, a tea party leader from Virginia.