Lt. Gov. Michael S. Steele won't officially become a candidate for U.S. Senate until next week, but his list of financial backers already is starting to look like a who's who of national Republican politics.

Since forming an exploratory committee in June, the Maryland Republican has received $10,000 apiece from political action committees affiliated with Senate Majority Leader Bill Frist (R-Tenn.), Senate Majority Whip Mitch McConnell (R-Ky.) and Sen. Elizabeth Dole (R-N.C.).

Dole heads the National Republican Senatorial Committee, the arm of the party charged with recruiting Senate candidates. Separately, that organization has pumped $37,000 into Steele's yet-to-be-formalized campaign.

Steele, who plans to make his bid official Tuesday, has also reaped personal donations from former Republican National Committee chairman Edward W. Gillespie, several former members of Congress and an array of lobbyists and former aides to Republican presidents and congressional leaders.

The donations are detailed in a fundraising report made public this week in which Steele lists about $418,000 for the quarter ending Sept. 30. About $120,00 came from national political committees, and at least $25,000 was from individuals identifiable as Washington lobbyists or consultants.

Steele boosters say the support from Washington shows a high level of enthusiasm for a politician widely seen as the GOP's best shot for reclaiming its first Senate seat from Maryland in nearly 20 years. The state has never elected an African American to the Senate.

But Democrats said yesterday that Steele's donor list could be a potential vulnerability in a state where Democrats hold a nearly 2-1 advantage. Steele has been heavily recruited by national Republicans to run, and Democrats argue that he would be beholden to them.

"He's a rubber stamp for the national Republican agenda," said Derek Walker, a state Democratic Party spokesman. "That's going to be the fundamental choice in this campaign: a person who's going to align themselves with President Bush or a man or woman who's going to represent Marylanders."

Leonardo Alcivar, a newly hired Steele spokesman, dismissed such talk as "silly," pointing out that Steele raised money from individuals across the state.

"The reality is that the lieutenant governor is a man whose leadership transcends ideology," Alcivar said. "Anyone who's spent time with him knows he's his own man."

Republicans and Democrats alike expect Steele's fundraising to ramp up considerably after he becomes a full-fledged candidate. His first publicly announced fundraiser during his exploratory phase was a $1,000-a-head event in July featuring presidential adviser Karl Rove.

Since then, Steele has taken donations from leadership PACs affiliated with the Senate's top GOP leaders as well as those of several newer members, including Sen. George Allen (Va.). Allen's Good Government for America Committee gave Steele $5,000.

Among the old Washington hands who have contributed personally is Charles R. Black, a GOP media consultant who said he has known Steele for years. "I think the others around town are impressed with him and his chances of winning the race," said Black, who gave $1,000. "We've had a long drought there."

Steele also has demonstrated some early success tapping the resources of national interest groups -- somewhat unusual for a candidate in the exploratory stages. Among the donors are PACs tied to the insurance, chemical and beverage industries and the National Thoroughbred Racing Association.

Dan Ronayne, a spokesman for the GOP senatorial panel who has been assisting Steele, said the interest in his candidacy in Washington is also evident in the actions of his counterparts at the Democratic Senatorial Campaign Committee. Two researchers there resigned this summer after improperly obtaining a Steele credit report.

"We're supporting Michael Steele because he will be a terrific candidate for the United States Senate," Ronayne said. "I think the actions of the Democrats say the same thing."

Democrats say Lt. Gov. Michael Steele, shown with Gov. Robert Ehrlich, was heavily recruited by national Republicans and would be beholden to them.