Liz Cheney has her work cut out for her. The former vice president’s daughter wants to represent her family’s home state of Wyoming in the U.S. Senate. To do that, she must beat incumbent Sen. Mike Enzi in the Republican primary next summer.

According to a Conservative Intel poll, Enzi starts with a 76 percent favorable rating—two points higher than Dick Cheney’s and an unfavorable rating that is ten points lower—and 73 percent job approval. If the election were held this month, Enzi would beat the younger Cheney by 34 points, 55 percent to 21 percent.

Despite a lackluster 67 percent rating from Heritage Action, Enzi doesn’t have any obvious vulnerability on abortion, marginal tax rates, guns, or the Gang of Eight immigration bill. He voted against the Wall Street bailout that did in Robert Bennett in Utah and hurt unsuccessful candidate Trey Grayson in Kentucky.

The two most obvious weaknesses: he is relatively unaccomplished—48 percent of Wyoming Republicans say he deserves reelection, compared to 28 percent who say he doesn’t and 24 percent who are undecided—and he supports the Marketplace Fairness Act.

The latter is a bill that would make it easier for states to collect taxes on online purchases. While supporters say it will achieve fairness for brick-and-mortar stores versus their Internet competitors, opponents claim it amounts to taxation without representation and would mean a red-tape nightmare for small businesses.

Grover Norquist and Arthur Laffer, two supply-side icons, have fought bitterly over the measure. It passed the Senate easily but remains stuck in committee in the House, where most Republicans seem to take Norquist’s side of the argument.

By itself, the Marketplace Fairness Act may be too obscure an issue to topple a sitting senator. Though many Wyoming residents buy things from out of state online, and would therefore be subject to more taxes, the money is on the side of the bill. Giants like Amazon have flip-flopped in favor of the legislation, deciding it’s better to smother the competition than promote a relatively tax-free Internet.

Yet Enzi’s MFA position could keep fiscally conservative groups that might be tempted to weigh in against Cheney’s high-priced neoconservative foreign policy—she is very much her father’s daughter on national-security issues—out of the race. It’s hard to see the Club for Growth or FreedomWorks lifting a finger for an online sales tax supporter.

Rand Paul won his primary in 2010 despite the opposition of hawks like Dick Cheney by uniting economic and social conservatives against the neoconservatives and the establishment. The neocons were further isolated when the establishment subsequently decided it was better to stand with Rand than lose one of Kentucky’s Senate seats.

Few of the conservatives elected to either house of Congress in Tea Party primary challenges are as skeptical of overseas military adventurism as Paul. But most of them are less hawkish than Cheney or, for that matter, Marco Rubio.

Utah Sen. Mike Lee has voted against extending the Patriot Act and warrantless wiretapping. He has also led the charge against the National Defense Authorization Act’s indefinite detention provision and supported accelerated troop withdrawals from Afghanistan.

Texas Sen. Ted Cruz has been more of a mixed bag, but he was willing back withdrawals from Afghanistan and didn’t go along with his primary opponent David Dewhurst in saying that residual American forces needed to remain in Iraq. Cruz sided with Paul and Lee on Patriot Act renewal and the NDAA, though he has sounded an uncertain trumpet in response to the recent NSA leaks.

Perhaps this is to be expected of a senator who was endorsed by both Ron Paul and Rick “Gathering Storm” Santorum and whose supporters span the GOP’s foreign-policy spectrum.

Cheney plans to flip the script, running as someone who will be a more combative conservative than Enzi in the same way that Cruz is more combative than Kay Bailey Hutchison—though you can bet there will be little emphasis on pleasing the Pauls or their supporters.

The odds are somewhat against her. Unlike her parents’, her roots in Wyoming aren’t that deep. She lived away from the state for years before reestablishing residency in 2012 with a home in Jackson Hole. Wyoming’s sole House member, GOP Rep. Cynthia Lummis, called Cheney’s candidacy “bad form” and expressed doubt that “anybody can out-conservative Mike Enzi.”

“It is a unique strategy to live your entire life elsewhere and then come to a state a year before you’re going to announce you’re going to run for that state’s highest office,” Lummis sniped. Aside from the carpetbagger charge, successful primary challenges normally hinge on one big issue or a series of prominent defections from the party line.

But in the Tea Party age, primary challenges based on temperament and seemingly esoteric issues have gone further than ever before. So Senator Cheney can’t be entirely ruled out.

W. James Antle III is editor of the Daily Caller News Foundation and author of Devouring Freedom: Can Big Government Ever Be Stopped?