A Texas grand jury indicted House Majority Leader Tom DeLay (R-Tex.) yesterday on a charge of criminally conspiring with two political associates to inject illegal corporate contributions into 2002 state elections that helped the Republican Party reorder the congressional map in Texas and cement its control of the House in Washington.

The indictment forced DeLay, one of the Republicans' most powerful leaders and fundraisers, to step aside under House rules barring such posts to those accused of criminal conduct. House Whip Roy Blunt (R-Mo.), the third-ranking leader, was elected by Republican House members yesterday afternoon to fill the spot temporarily after conservatives threatened a revolt against another candidate considered by House Speaker J. Dennis Hastert (R-Ill.).

Although the indictment had been rumored for weeks among top Republicans, based on what several described as a difficult meeting in August between DeLay and the Texas prosecutor behind the case, it shook the GOP political establishment and posed new problems for the party as it heads into the midterm elections next year.

DeLay bitterly denounced the charge as baseless and defiantly called the prosecutor, Ronnie Earle, "an unabashed partisan zealot" engaging in "personal revenge" because DeLay helped elect a Republican majority to the Texas House in 2002. "I have the facts, the law and the truth on my side," DeLay said, reading from a statement, before declining to answer questions.

But the indictment, which comes after three rebukes of DeLay in 2004 by the House ethics committee on unrelated matters, poses a major political problem for the 58-year-old Bush administration loyalist, 11-term congressman, and self-described champion of free enterprise and deregulation. DeLay is also likely to face an inquiry by the ethics committee into a series of foreign trips he took that were initially partly paid for by lobbyists.

The indictment specifically alleges that DeLay, who helped organize the Texas political committee at the heart of the charge, participated in a conspiracy to funnel corporate money into the 2002 state election "with the intent that a felony be committed."

Using corporate funds for state election purposes has long been illegal in Texas, as it is in 17 other states. Earle's probe of the contributions began after 17 Republicans who received the committee's funds were elected, giving the party control of the Texas House for the first time in 130 years. One year later, following a road map that DeLay and his political aides drafted from Washington, the Texas House approved a sweeping reorganization of the state's congressional district map meant to favor Republicans.

Then, in 2004, five more Texas Republicans were elected to Congress, enlarging the Republican majority in the House .

The facts of one of the central transactions at issue in the case have never been in dispute -- the transfer in September 2002 to an arm of the Republican National Committee in Washington of $190,000 in corporate funds collected by the committee in Texas and the subsequent donation by the RNC arm of $190,000 to seven Texas House candidates on Oct. 4, 2002.

Earle has long alleged that this transfer was intended to circumvent the Texas law. A copy of the relevant check from the Texas committee has been in his hands for more than a year, and he has repeatedly said the committee supplied the RNC with a list showing which Texas candidates should eventually be paid the funds.

Some evidence collected in a related civil case has pointed to heavy involvement by DeLay in the operations of the Texas committee. Its start-up was financed by a transfer of corporate funds from his leadership fund. He was a member of the Texas committee's advisory board in 2001 and 2002, participated in its strategizing, appeared at its fundraisers, and signed its solicitations. He also attended dinners with corporate donors that agreed to contribute tens of thousands of dollars to it; his fundraisers recorded the favors that donors sought.

But DeLay has long denied participating in its day-to-day operations and said that its activities were vetted by lawyers. As a result, the key question in Washington and Austin has been whether DeLay knew about the $190,000 transactions -- an allegation that lawyers say could be proved only by documentary evidence, such as an e-mail, or in grand jury testimony by one of those involved.

For DeLay to be guilty, he would have had to have both been informed of the transaction and approved the transaction, according to a source familiar with the details of case. David Berg, a Houston-based trial lawyer who wrote a best-selling legal textbook, said: "Politics in Texas is a real jungle, and money of this sort, I would suspect, gets washed all the time. [But] it would be illegal if [he] knew that corporate funds were going to be laundered and used in the state races. . . . I can't imagine somebody is not going to testify against [him]. Otherwise all Ronnie Earle can prove is that everything DeLay did is legal."

No evidence to support the conspiracy charge was cited in the indictment, which says only that DeLay and two named associates entered "into an agreement with one or more of each other" or with the committee to conduct the funds transfer. But Texas law permits such evidence to be left out of the indictment, so it is rarely included.

The others named in the indictment were James W. Ellis, who still runs DeLay's principal fundraising committee -- Americans for a Republican Majority -- and John D. Colyandro, the former director of the Texas offshoot. Both were previously charged with laundering money, an offense that can bring a 10-year prison term, and on Sept. 13 with conspiracy to accept illegal corporate donations.

The addition of DeLay to the conspiracy charge yesterday suggests that some crucial piece of information or testimony may have come into Earle's possession in recent weeks. The charge against DeLay carries a potential penalty of six months to two years in state jail, and a fine of as much as $100,000.

DeLay's attorney, Dick DeGuerin, said in the lobby of the Austin Criminal Justice Center that DeLay is so confident of his innocence that he will push for a swift trial. He said DeLay did not participate in a conspiracy and the $190,000 was spent "on proper things."

J.D. Pauerstein, an attorney for Ellis, said: "All of the indictments handed down in this case are frivolous and ridiculous. Our clients consulted election law experts, followed their advice and reported every contribution" to the Internal Revenue Service.

Colyandro, a veteran of White House Deputy Chief of Staff Karl Rove's direct-mail firm, has long denied wrongdoing but lost several court battles since the inquiry began to have the relevant Texas election law declared unconstitutional. His attorney in Austin, Joseph A. Turner, said that "this is really a rehash of previous indictments" and that the lengthy wait for it reflected the weakness of the prosecutor's case.

Regarding the $190,000 funds transfer from Texas to Washington and the return of the same amount from Washington to Texas, "Colyandro would say DeLay did not have any knowledge of that transaction in advance," Turner said.

The new indictment came after a 34-month inquiry and was issued on the final day the grand jury met. It caps a series of indictments that targeted eight corporations and an industry group, the Texas Association of Business, alleged to have worked with the Texas committee in collecting and disbursing illegal corporate contributions.

DeLay waived a requirement that the indictment be presented within three years of "the commission of the offense," the document states; DeGuerin said DeLay did this under duress so that he could put off an indictment weeks ago and keep trying to persuade Earle not to bring one.

Earle told reporters that he brought the indictment to defend the state's democratic system from undue corporate influence. "The law says the duty of a prosecutor is to make sure justice is done," Earle said, adding that the ban against corporate contributions "is intended to safeguard democracy and make the ballot box accessible to everybody, regardless of the amount of money involved."

But DeLay spokesman Kevin Madden said ill motives lie behind Earle's action: "They could not get Tom DeLay at the polls. They could not get Mr. DeLay on the House floor. Now they're trying to get him into the courtroom. This is not going to detract from the Republican agenda."

House Speaker Hastert, surrounded by other GOP leaders, said of DeLay: "He will fight this, and we will give him our utmost support." Blunt complained about "this terribly unfair thing that ha happened to him."

House Democratic Leader Nancy Pelosi (Calif.) said, "The criminal indictment of Majority Leader Tom DeLay is the latest example that Republicans in Congress are plagued by a culture of corruption at the expense of the American people."

But White House spokesman Scott McClellan described DeLay as "a good ally, a leader who we have worked closely with to get things done for the American people."

"I think the president's view is that we need to let the legal process work," he added.

"No jury can undo the outcome of Texas's 2002 elections," Craig McDonald, director of Texans for Public Justice, said in a news release. McDonald, whose complaint helped spark Earle's investigation, continued: "But the justice system must punish those who criminally conspire to undermine democracy -- no matter how powerful they may be. If we are to be a 'democracy,' then powerful politicians cannot flout such laws with impunity."

Staff writers Juliet Eilperin in Austin and Jeffrey H. Birnbaum and Amy Goldstein in Washington contributed to this report.

"I have the facts, the law and the truth on my side," said Rep. Tom DeLay, who is in his 11th term in Congress.Rep. Tom DeLay stepped down as majority leader shortly after the indictment was announced, as required by House rules.