The decision by Judge Pat Priest narrowed the allegations DeLay must face in the trial, but meant that powerful Republican cannot reclaim his leadership post. Under House rules, no one under criminal indictment can hold a senior position.
When he was initially indicted in September, DeLay scoffed at the charges, calling it "one of the weakest, most baseless indictments in American history. It is a sham, and [Travis County District Attorney Ronald] Earle knows it."
The judge threw out the conspiracy charge, ruling that the actions of DeLay and two co-defendants were not a crime at the time the three were charged with violating them.
DeLay and his colleagues Jim Ellis and John Colyandro have all denied any wrongdoing stemming from their work for the Texans for a Republican Majority Political Action Committee (TRMPAC). Instead, they have accused Earle of heading a Democratic political witch hunt against the conservative Texan.
But the three still face charges that they laundered $190,000 in corporate donations to TRMPAC through the Republican National Committee for use by Republican candidates to the Texas Legislature in the 2002 state campaign. Under Texas law, corporate money cannot be directly used for political campaigns, but it can be used for administrative purposes.
Despite the continuation of the money laundering case, a spokesperson for DeLay hailed Monday's ruling.
"The court's decision to dismiss Ronnie Earle's numerous charges against Mr. DeLay underscores just how baseless and politically motivated the charges were," DeLay spokesman Kevin Madden said.
"Mr. DeLay is very encouraged by the swift progress of the legal proceedings and looks forward to his eventual and absolute exoneration based on the facts and the law."
Money laundering is punishable by five years to life in prison. Conspiracy to commit money laundering carries two years.