There has been only one case in Texas where voter fraud has been alleged. Several people have been arrested and indicted.
Details are here:
Seven indicted for voter fraud in RUD election - Your Houston News: The Woodlands Villager: News
Many sources, including the Defendants themselves, have alluded to the possibility that all of the indicted are strong supporters of the Tea Party.
The gist of the matter is that very few voters were expected in this election which would elect members of a Rural Utilities District. The RUD decides on the amount of taxes to levy and if an RUD can join in with other RUD's or a city. In The Woodlands only businesses are taxes on property and not homeowners, and the RUD has the power to change this.
Just a few votes would be needed to throw the election, so these guys are supposed to have stepped up to the plate and committed voter fraud.
At least that is what the Attorney General of Texas is alleging. A trial is yet to be held.
The voting in question took place over a year ago, but the Republican Attorney General of Texas took a long time before bringing any charges. The rumor going 'round is that the Defendants bragged to a number of people about what they did and this sort of forced his hand on the matter, but that is just a rumor. It could be the Attorney General was too busy looking for other cases of voter fraud but finally gave up since there don't appear to be any.
I am sure all the facts about this will come out during the trials.