HOUSTON — In the six days Tom DeLay has been on trial, prosecutors have called 22 witnesses and presented volumes of e-mails and other documents as they try to convince a jury that the former U.S. House majority leader illegally funneled corporate donations to Texas GOP candidates in 2002.

So far, no witness or document has directly tied DeLay to the alleged scheme, and some courtroom observers are questioning how strong the prosecution's case is.

"I guess we have to give (prosecutors) the benefit of the doubt. They haven't finished their case yet. But what I've seen so far is troubling," said Bradley Simon, a New York white collar criminal defense lawyer who has been following the trial.

DeLay is charged with money laundering and conspiracy to commit money laundering. Prosecutors allege he and two associates — John Colyandro and Jim Ellis — illegally channeled $190,000 in corporate donations collected by DeLay's Texas PAC through the Washington-based Republican National Committee. Under Texas law, corporate money can't go directly to political campaigns. Testimony was to resume Wednesday.

Former PAC fundraisers, lobbyists and Texas candidates who allegedly received illegal corporate donations have detailed for jurors how DeLay's PAC worked, the donations it received and problems it was having in raising money from individual donors — the only type of funds that could go to political campaigns under Texas law. Prosecutors have implied DeLay was the driving force behind the PAC and the alleged scheme to "clean" the corporate donations through a money swap they say couldn't have been done without his knowledge.

The former Houston-area congressman denies wrongdoing. He faces up to life in prison if convicted.

Prosecutors say the money helped Republicans take control of the Texas House in 2002. That majority allowed the GOP to push through a Delay-engineered congressional redistricting plan that sent more Texas Republicans to Congress in 2004 and strengthened DeLay's political power, prosecutors said.

Amid the prosecution's case, DeLay's attorneys have told jurors that DeLay was only a figurehead and had little if any involvement in how the PAC was run, that the money swap was legal and common, and that the money sent by the Republican National Committee didn't come from corporate donations.

Lead prosecutor Gary Cobb said the circumstantial evidence presented at trial is important to proving the case.

"Further evidence will tie him directly," Cobb said.

DeLay and his attorneys don't believe prosecutors have presented any evidence he committed a crime.

"What case?" DeLay said. "When are they going to connect the dots? People may not like the fact that corporate money goes into politics, but it's nothing criminal."

DeLay's own words could be used against him as prosecutors planned to present to jurors on Wednesday a statement he gave to authorities before his 2005 indictment in which he allegedly said he knew beforehand about the $190,000 transaction. DeLay has said that he misspoke to prosecutors and didn't know about it until much later.

DeLay's attorneys have said the charges against him were politically motivated, which prosecutors deny.

The criminal charges in Texas, as well as a separate federal investigation of DeLay's ties to disgraced former lobbyist Jack Abramoff, ended his 22-year political career representing suburban Houston. The Justice Department probe into DeLay's ties to Abramoff ended without any charges filed against DeLay.

Ellis and Colyandro, who face lesser charges, will be tried later.

DeLay, whose nickname was "the Hammer" for his heavy-handed style, now runs a consulting firm based in the Houston suburb of Sugar Land. In 2009, he appeared on ABC's hit television show "Dancing With the Stars."