WASHINGTON — Capitol Hill will be abuzz today with the arrival of a new class of Republican lawmakers who charged into office with a promise to shun the ways of Washington.

But even as they publicly bash the capital’s culture, many have quietly begun to embrace it.

Several freshmen have hired lobbyists — pre-eminent Washington insiders — to lead their congressional staffs. In the weeks leading up to today’s swearing-in, dozens of the newcomers joined other lawmakers in turning to K Street for campaign cash. Congressional offices will be packed today with lawmakers’ relatives, friends, constituents and lobbyists, all invited to celebrate the new Congress.

This picture of business-as-usual Washington clashes with the campaign rhetoric of many newcomers, some who were propelled by support from the anti-Washington tea party. It also muddles the image House Republicans hoped to project as they take the helm this week. In contrast to the public celebration thrown by Rep. Nancy Pelosi, D-San Francisco, when she became speaker four years ago, incoming House Speaker John Boehner has tried to strike a subdued and earnest note as he takes the gavel.

So it raised eyebrows Tuesday when several House freshmen held a big-dollar fundraiser in a swanky Washington hotel. The event, organized in part by Rep.-elect Jeff Denham, R-Modesto, stood out as the flashiest celebration of the new Congress — and an early and public acknowledgement that while some things change, many stay the same.

“It’s important. Without money, the machine doesn’t move,” GOP strategist and fundraiser Javier Ortiz said about the swearing-in week schedule of fundraisers and other events. “No one should be surprised that newly elected or long-serving members ask interested constituents and others to support their campaigns by making donations.”

Still, the Tuesday night fundraiser at the W Hotel was not celebrated by House leaders. Boehner declined to attend. The offices of incoming Majority Leader Eric Cantor, R-Va., and Majority Whip-elect Kevin McCarthy, R-Bakersfield, did not respond to a request for comment on the event, though one of the hosts said McCarthy had committed to attend.

The fundraising event was hosted by the New Majority PAC, a committee formed in November by Denham, a former state senator, as well as incoming GOP Reps. Steve Southerland of Florida, Renee Ellmers of North Carolina, Robert Dold of Illinois and Scott DesJarlais of Tennessee. Southerland, Ellmers, Denham and DesJarlais all enjoyed tea party support.

Talking with reporters before the event began, Denham said the PAC was formed to help make the freshman class of Republicans “self-reliant so we will have all the funds we need to hold our seats.” He said the fundraiser, featuring country singer LeAnn Rimes, was held to mark “an exciting time for our nation.” He made no apologies about the $2,500-per-ticket entry fee.

“Unfortunately, campaigns are expensive,” he said. “We all know the Democrats are out there raising money.” He told reporters that he expected “a number of tea party members will be here with us tonight.”