The Republican presidential primary field is shaping up to have about a dozen contenders in 2016, and U.S. Sen. Ted Cruz of Texas may become one of them. But if Cruz decides to mount a campaign, his biggest strength -- strong support among conservative, tea party voters – may also be his biggest liability.  

While he hasn’t yet officially announced a run for president, Cruz has said he is strongly considering it. In October, he made a visit to the Wichita, Kansas, headquarters of the oil billionaire Koch brothers to make the case that Republicans need a grassroots conservative as their nominee in 2016, according to the New York Times. He’s also hired staff in the key early states of Iowa, New Hampshire and South Carolina -- a strong signal that he's serious.

Cruz’s reputation as a uncompromising firebrand who shut down the federal government over Obamacare has made him a hero of the tea party. And these are the kind of voters who are the likeliest to turn out for primaries in 2016.

“If there’s Texas grit, Ted’s got it,” said political consultant Suzanne Bellsynder of the Austin, Texas-based Bellsnynder Group, who worked with Cruz when they were both staffers, he in the state attorney general’s office and she in the Texas state Senate. “He’s one of the people who’s relentless. He’s works hard, he’s smart, he’s not afraid to take on things that are a little bit edgy … and primary voters are looking for that kind of leadership.”

If that is what Republicans are looking for, they don’t know it yet. Cruz is running in the low single digits in the latest polls in Iowa and New Hampshire, the first caucus and primary states. To improve his standing, he’s going to have to broaden his appeal beyond the tea party, according to Bruce Buchanan, a political science professor at the University of Texas at Austin.

“This is an amazingly talented fellow. Tons of energy, but he’s at this moment almost more of a message politician in that he has a point of view but not an extraordinary base of support outside the state of Texas, where he is quite popular,” Buchanan said. “He hasn’t displayed the ability yet nor had the opportunity to display the willingness to build coalitions toward the center right now, and that’s what he’ll have to do to move to a position of greater credibility. The establishment wants to win in 2016, and now he looks like a fringe candidate that sets up for defeat.”

As Cruz considers a 2016 run, the main focus right now is finding donors. Cruz should have no trouble with what Bellsnyder calls “heart donors,” or those who contribute to candidates who align with their political views. But he may struggle with “investment donors” with deep pockets who want a viable candidate.

“They may like him, they may believe in him and what he’s trying to do. But from the donor perspective, they’re making a decision on what’s a good business decision for them,” Bellsnyder said. “In a lot of ways, fundraising is marketing. You have to show people how you’re going to get there.”

While Cruz has been touted for offering ethnic diversity -- his father was born in Cuba -- his position against granting a path to citizenship for illegal immigrants hasn’t played well with many Hispanic voters. There are no exit polls from Cruz’s 2012 Senate victory, but an ImpreMedia/Latino Decisions poll the day before the election showed only 35 percent of self-identified Latinos supported Cruz -- only six points better than the 29 percent GOP presidential nominee Mitt Romney received among Latinos in Texas. He also only got 26 percent support among naturalized citizens and 26 percent of the Spanish-speaking vote in Texas.   

Cruz’ showing among Texas Hispanics in 2012 doesn't bode well for his chances in 2016, when the group will be one of the key voting blocs in a general election. Hispanics in Texas are heavily Mexican-American and Cubans are a significant bloc only in Florida, where they will have their own favorite son if Sen. Marco Rubio runs. Jeb Bush also has run well with Florida Hispanics.

Another knock on Cruz is his inexperience, having only been in the Senate for a little more than two years. His swift ascent from unknown to rising star mimics the path of President Barack Obama, who also had less than one term in the Senate when he was first elected in 2008. The Senate is Cruz’s only elected political office; he served as the appointed solicitor general of Texas from 2003 to 2008.

“The ‘young man in a hurry’ charge will come up for sure,” Buchanan said.

It has already been lobbed at Cruz. Without mentioning him by name, former Texas Gov. Rick Perry, a potential rival in 2016, recently said he thinks the American people are “going to make a rather radical shift away from a young, untested United States senator whose policies have really failed,” according to the Washington Post.