PPP’s final poll of the Republican Senate runoff in Texas finds Ted Cruz opening up a 52-42 lead, an increase from our survey two weeks ago that found him ahead 49-44.

Cruz’s victory is driven by 4 things: the Tea Party, the enthusiasm of his supporters, a generational divide within the Texas Republican ranks, and the lack of regard the party base currently holds for Rick Perry.

Cruz is ahead by a whooping 75-22 margin with Tea Party voters, more than making up for a 56-39 deficit to Dewhurst with voters who don’t consider themselves members of that movement. There has been too much of a tendency to ascribe any Republican primary upset over the last few years to Tea Party voters, but this is one case where it’s well justified.

Cruz has a 63-33 advantage with voters who describe themselves as ‘very excited’ about voting in Tuesday’s runoff election.