Prosecutors spoke to jurors first on Monday. Defense attorneys were to follow with their final presentation before prosecutors wrap up closing arguments and then hand the case over to jurors.
Prosecutors allege DeLay used his political action committee to illegally channel $190,000 in corporate donations into 2002 Texas legislative races through a money swap.
DeLay denies wrongdoing. He and his attorneys say no corporate money went to Texas candidates and the money swap was legal.
The once powerful but polarizing Republican Houston-area congressman faces up to life in prison if convicted.