Under Texas law, it is illegal for candidates to use corporate money -- raised directly or indirectly -- for their campaigns.
Prosecutors said the swap constituted money laundering. DeLay and his lawyers argued that it was a perfectly legal transaction.
The crux of the prosecution's case was proving DeLay knew about the swap beforehand. DeLay's defense said he didn't know about it until afterwards.
The prosecution gained the upper hand with the tape of a 2005 interview in which DeLay told investigators he knew about the swap beforehand. He later said he misspoke. The prosecution also gained a surprise boost when the defense, apparently accidentally, revealed a calendar that showed DeLay had met with his PAC's director just hours after he cut a check for the RNC.
DeLay maintained that the swap was still legal. He did not testify.
All seven of the state house candidates won, putting the Texas legislature back in Republican hands for the first time in a century and leading to a DeLay-lead redistricting effort that put more Republicans in the U.S. House and gave DeLay himself more power.
His two alleged co-conspirators -- aides who led TRMPAC -- will also face trial.
Much, much more on the trial here.