"The mantra now in the Republican primary is you cannot be too conservative," said Mark Jones, chairman of political science at Rice University.
There's plenty of evidence to back that line of thinking in the latest UT/ Texas Tribune Poll where relative political newcomer Tea Party backed Ted Cruz has crept within nine points of Dewhurst (40% to 31%).
That means for the sitting Lt. Governor hope of avoiding a head to head battle later this summer has become a long shot.
"I think we are looking at a runoff between Ted Cruz and David Dewhurst on July 31st," predicted Jones.
Cruz, whose collected the backing of uber conservatives Sarah Palin, Sean Hannity and Rand Paul spoke with Fox 26 on route to a trio of West Texas campaign stops.
"This race is ground zero in the battle between the moderate establishment and the Tea Party title wave of new leadership that is sweeping the country," said Cruz.
Jones says the top flight Tea Party endorsements effectively counter Dewhurst's high dollar broadcast campaign accusing Cruz of being a false conservative.
"For the majority of Republican primary voters Sarah Palin's more credible than a Dewhurst attack ad," Jones explained.
Former Dallas Mayor Tom Leppert trailed Dewhurst and Cruz with support from 17 percent of those responding to the UT/Tribune poll.