It wasn’t supposed to be this way. Republicans in Washington wanted North Carolina House Speaker Thom Tillis to quickly win the party’s Senate nomination and focus entirely on vulnerable Democratic incumbent Kay Hagan.

Instead, Tillis faces a May 6 primary that’s so crowded it may be hard for any candidate to muster the 40 percent needed to avoid a mid-July runoff. The race also pits two leaders -- Kentucky U.S. Senators Mitch McConnell and Rand Paul -- against each other in a proxy battle over the party’s future.

Tillis must balance support from national Republicans against the Tea Party’s anti-Washington instincts. Fundraisers he held late last year with Karl Rove, former President George W. Bush’s key political adviser, turned off activists in the limited-government movement.

“When he brought in Karl Rove, that knocked him out of the running for me,” said Ann Hilburn, a retired U.S. customs worker from Wilmington, North Carolina. “Karl Rove is a moderate and he doesn’t like the Tea Party.”

The party infighting unnerves some Republicans who worry it could weaken the nominee in a state that may be central to the party winning a majority in the U.S. Senate. Republicans need a net gain of six seats to take control, and the nonpartisan Cook Political Report in Washington lists North Carolina as a “tossup.”

Most polls show Hagan, a first-term senator, in a tight race with her eventual Republican opponent. She’s faced a steady flow of anti-Obamacare attack ads financed by Americans for Prosperity, a group funded by billionaire energy executives Charles and David Koch. Republican presidential nominee Mitt Romney narrowly carried the state in 2012, after President Barack Obama won it in 2008.

Splintered Base

Reflecting Hagan’s vulnerability, eight Republican candidates filed for the primary, splintering the party base.

Hilburn, the customs worker critical of Rove, was at last week’s monthly meeting of the North Brunswick Republican Club, a gathering where the division and angst bubbling through the party was on display.

About 40 people assembled in a banquet room in the state’s Cape Fear region to hear Greg Brannon, a Tea-Party aligned contender in the primary who took repeated jabs at Tillis.

“A moderate Republican will lose to Ms. Hagan,” said Brannon, 53, an obstetrician, father of seven and first-time candidate who lives in a Raleigh suburb.

In an interview, Tillis countered: “A runoff benefits no one but Kay Hagan. It takes time off the clock, it gives her seven more weeks before everyone can turn their attention to the real goal, which is to unseat her, and it costs money.”

Pragmatic Choice

Randy Hendren, a recent retiree from a business planning job with a chemical maker, voiced similar concerns during the Republican club’s meeting.

“When I go to the polls on May 6, I’m going to balance who most fits what I believe in, but I’ve also got to balance that against who I think is going to beat Kay Hagan,” he said. “At the end of the day, we have to get rid of Kay Hagan.”

Hendren said he was living in Delaware in 2010 when then- U.S. Representative Mike Castle was upset in a Republican Senate primary by Christine O’Donnell, a Tea Party favorite who during the general election campaign was forced to deny she was a witch and went on to lose to a Democrat. He said North Carolina Republicans need to take a more pragmatic approach.

“I like this guy,” Hendren said of Tea-Party favorite Brannon. “But the odds are better for the speaker.”

Tillis, who lives in the Charlotte area, says he’s nothing close to a “moderate,” and has been part of state leadership that’s put forward “as successful a conservative agenda of any state over the last three years.”

Legislative History

During his leadership, the state has cut taxes and spending, passed an amendment that defines marriage as the union of one man and one woman, and enacted some of the nation’s strictest voting requirements.

The state’s unemployment rate was 6.7 percent in January, just above the national rate of 6.6 percent that month. The North Carolina rate is well below its recent-historic peak of 11.3 percent in early 2010.

Brannon received a boost in October when Paul, a potential 2016 Republican presidential candidate and Tea Party star, backed his candidacy. He also has the support of FreedomWorks, a Washington-based advocate for small government.

Tillis, 53, has won most of the endorsements from more established Republican figures, including McConnell, who faces his own Tea Party primary challenge in Kentucky on May 20.

Huckabee Endorsement

Besides Brannon and Tillis, one other candidate has received an endorsement from a big Republican name. Mark Harris, 47, a Baptist pastor from Charlotte, is backed by former Arkansas Governor Mike Huckabee, another prospective 2016 presidential aspirant.

“In order to defeat her, it is going to take a unique candidate that can offer that fresh face, that fresh perspective -- not of a professional politician, but more of a statesman and someone with principled leadership,” Harris said in an interview.

Brannon has had to deal with ethical questions after a court judgment earlier this month requiring him to pay two investors in Neogence Enterprises Inc., his failed startup company, more than $450,000.

Legal Trouble

The judgment followed a February jury verdict that found he bore sole responsibility for giving misleading or false information in 2010 to investors about a mobile application being developed by the now-defunct technology company he helped create. He’s appealing the jury’s verdict.

A survey by Public Policy Polling, a Democratic-leaning research firm based in Raleigh, found Brannon and Tillis tied at 14 percent. The poll of likely Republican primary voters was conducted March 6-9 -- after news of the court judgment -- and had an error margin of plus or minus 5 percentage points.

The state’s business community is rallying behind Tillis, a former partner at business consultant PricewaterhouseCoopers. The North Carolina Chamber gave him a 96 percent rating on votes the group tracked in 2013.

In its annual report, the chamber said Tillis earned “high marks as a jobs-focused, business-minded leader.” Spokeswoman Meredith Archie declined to comment on the primary, citing the group’s tradition of not weighing in on federal contests.

“He very much functions with that type of business acumen,” said Elbert Boyd, the owner and chief executive officer of a E. Boyd & Associates, Inc., a global frozen food distributor in Raleigh. “I really admire the man for being able to lead the legislature as he did.”

Allen Gant, chairman and chief executive officer of Glen Raven Inc., a global fabric company based in Burlington, North Carolina, said Tillis has worked hard to make the state more business-friendly.

“I hope that the voters in North Carolina will recognize that Thom is a proven entity,” he said. “He did an incredible job of pulling the different sides together and acted like a real statesman.”