Prosecutors allege that the case was part of conspiracy to support candidates that backed expanding Indian gambling or relaxing restrictions on interstate trucking.  The charges allege that the money was donated illegally to President Bush, Wisconsin Gov. Jim Doyle and others.

The conspiracy was run out of the Kenosha, Wis.-office of trucking company JHT Holdings Inc., the charges said.

According to the charges, Erickson helped control the cash fund made up of corporate money and other sources that was used to reimburse contributions to the campaigns of more than 20 candidates from January 2002 through March.

U.S. Rep. Paul Ryan, R-Wis., received donations as did Bush, Doyle and the political action committees of both the Republican and Democratic parties, the charges allege. While more than 20 candidates benefited from the money, no candidates have been charged with any wrongdoing.

The object of the conspiracy, according to the charges, was to evade state and federal donation limits, make illegal donations to candidates "aligned with the business interests of the conspirators," and illegally reimburse contributions made by co-conspirators and their family members.

The charges allege that Erickson worked in part with Dennis Troha, who until last year was the owner of JHT Holdings. As part of a deal with prosecutors, Troha pleaded guilty in July to making illegal campaign donations both to the Democratic Party and President Bush.

Troha had been leading the effort to build a new casino in Kenosha in partnership with the Menominee Tribe. He pulled out of the project in February just days before he was indicted. In order for a new casino to be built, it must be approved by federal authorities and the governor of Wisconsin.

Doyle, who was re-elected to a second term in November, has received more than $200,000 in donations from Troha and his family members. He has refused to return any of the money and repeatedly denied that there were expectations from Troha that the money was given in exchange for Doyle's approval of the casino project.

Biskupic's charges allege that members of the conspiracy, including Troha, singled out public officials who supported Indian gambling or relaxing restrictions on interstate trucking. Campaign contributions were then made in excess of individual limits or other state and federal restrictions, the charges allege.

Troha made his mark in the specialized trucking industry. He joined the former Kenosha Auto Transport in 1974 and later became a principal owner of its successor firm, ATC Leasing. That company later became a subsidiary of Troha's JHT Holdings. He sold off a majority of the company to a private equity firm in February 2005 and severed all ties with JHT last year.

Lawmakers who championed legislation backed by Troha that went into effect in 2005 also received money from Troha and those around him.

Reps. Don Young, R-Alaska, and Jim Oberstar, D-Minn., at the time the chairman and ranking member, respectively, of the House Transportation Committee, both received more than $20,000 from Troha, his family members and associates.

Ryan had written to Young and Oberstar urging them to support the new regulations. He received $58,000 from Troha and his family members that he donated to the Kenosha Boys & Girls Club after Troha's indictment.

Biskupic's charges allege that one part of the conspiracy involved giving loans to family members who were not asked to repay them until after FBI agents questioned members of the conspiracy about their contributions.

Conspirators also illegally gave family members and others direct cash reimbursements for campaign contributions, the charges allege. Reimbursements were made from a large pot of money which included a significant amount of corporate money, the charges allege.

The conspirators' actions caused federal recipients of the money to file false reports with the Federal Elections Commission, the charges allege.

Erickson made contributions knowing the money would be reimbursed through prohibited sources, falsified corporate expenses and diverted corporate income to a cash fund, the charges allege.

Biskupic said the investigation, which is headed by the FBI in Milwaukee, is ongoing.

(The Associated Press contributed to this report)