AUSTIN — Political experts have a bit of advice for Lt. Gov. David Dewhurst’s re-election campaign: go negative or go home.The incumbent Senate president was crushed in Tuesday’s Republican primary by Houston Sen. Dan Patrick.In all, more than 72 percent of the roughly 1.3 million Texans who cast ballots in the GOP lieutenant governor’s race voted against Dewhurst, an 11-year incumbent who out-raised and outspent his three competitors in the field.Now Dewhurst, who pulled just 27 percent of the primary vote, faces much more than an uphill climb in the May runoff.To even stand a chance, Dewhurst will need to convert hundreds of thousands of voters who backed Agriculture Commissioner Todd Staples andor Land Commissioner Jerry Patterson — no easy task in itself, and neither Staples nor Patterson has lined up behind Dewhurst yet.Political experts say the multimillionaire Dewhurst will need to unleash a barrage of attacks aimed at loosening Patrick’s stranglehold on the base of Texas’ most conservative voters, the same group that will decide the May runoff.“Dewhurst has got to do that by trying to disrupt the image that Patrick’s established among them. That means going negative,” said Jim Henson, director of the Texas Policy Project at the University of Texas at Austin. “The argument has to be to try to convince Patrick’s voters they’ve been sold a bill of goods. At this stage of the game it’s a pretty tough sell.”It could prove impossible altogether.Used Cruz’s formulaPatrick, already a tea party darling, continually pivoted to the furthest right of the field with ease throughout the campaign, often requiring his three opponents to follow suit just to keep pace. Late in the campaign, he successfully shrugged off an attack showing he hired undocumented workers in the 1980s, in part by labeling it an assault lobbed by the established political machine trying to derail his grass-roots momentum.Patrick, late Tuesday evening, even touted how he used the same formula put in place by Ted Cruz to trample Dewhurst in the 2012 runoff for U.S. Senate: Attract the tea party like a magnet, stir up controversy, and repeat.“We had probably 95 percent of the people who supported Ted Cruz supporting us. They are activists,” Patrick said.That the northwest Houston senator toppled Dewhurst in Tuesday’s primary came as huge surprise to most observers, who believed the talk radio host was poised to finish second.Launching a series of attack ads could have consequences for Dewhurst. In 2012, he aggressively attacked Cruz — and it mostly backfired. Tea party voters to this day remember the tactic.Cruz, himself, described the Dewhurst strategy as “nasty, false attack ads trying to convince every Texan that I’m a red Chinese communist who wants to eat your children.”Going negative against Patrick was a big part of the late strategy for Staples and Patterson. It failed.The two candidates drew a combined 400,000 voters, which amounted to about 29 percent of the vote, according to the secretary of state’s office. Patrick alone got more than 550,000 votes, outpacing Dewhurst by about 175,000.Gaining the support of Patterson and Staples voters is now the goal for the two runoff candidates, and Dewhurst wasted no time pivoting to that bloc Tuesday night.“They both ran a good and tough race. You ought to be proud of them,” Dewhurst said, adding, “I think you are going to discover that there is more that unites us than divides us.”Strategy has drawbacksMark Jones, a political scientist at Rice University, said that moving forward “the only plausible route for Dewhurst is to go completely negative.” Such a strategy has its drawbacks, he added.“Right now, if you’re a cold and calculating Republican donor and if you give money to Dewhurst and he goes negative on Patrick, you’re creating an enemy in Patrick and further antagonizing movement conservatives,” Jones said.Meanwhile, Dewhurst’s team is left digging for clues on how it got beaten so badly in a primary that it had been expected to win.Hotze’s mailers a factorOne of the keys could have been slate “mailers” distributed by influential Republicans. Dewhurst’s supporters groused on election night that a mailer from Houston physician Steven Hotze’s political action committee contributed to the lieutenant governor’s poor showing, since Hotze endorsed Patrick.Hotze’s Conservative Republicans of Texas PAC spent $1.2 million distributing a mailer that endorsed a slate of conservative candidates, and included an application for a mail-in ballot, according to his political consultant, Allen Blakemore.Hotze, he said, made 224 endorsements in the Republican primary; 194 of those candidates won, and 18 others are in runoffs.“It’s been a very successful program,” Blakemore said. He estimated that voter participation by mail-in ballots increased some 4 percent this year — and he attributed that increase, in part, to Hotze’s effort.As it turned out, tax consultant G. Brint Ryan, a member of Dewhurst’s finance team, contributed $200,000 to Hotze’s PAC.“Brint Ryan looked at what Dr. Hotze does and said, ‘I think that’s helpful and I want to support it,’ ” Blakemore said. He also said he doubted that any of Hotze’s contributors agreed entirely with all 224 endorsements.