U.S. Republican presidential candidate Ted Cruz speaks at a campaign rally in Dallas, Texas February 29, 2016. Mike Stone/Reuters If Republican Presidential hopeful Ted Cruz lands a win in the nominating contest in his home state of Texas on Tuesday, part of the credit will go to support from a small and often overlooked interest group: homeschoolers.

The Senator's campaign has invested months of effort courting the well-organized network of families who educate their children at home - often to avoid constraints on religion in public school - in the hopes they can keep a big chunk of conservative voters away from his rivals, billionaire Donald Trump and Senator Marco Rubio of Florida.

"They were crucial to our win in Iowa and will be in Texas (as well)," said Cruz campaign spokeswoman Catherine Frazier, referring to Cruz's only victory in a string of four contests for the party's presidential nomination so far that have otherwise been swept by Trump.

The Cruz campaign has used its message of religious liberty and small government to draw some 6,670 members to its "Homeschoolers for Cruz" coalition in recent months - many of whom campaign on his behalf.

"One thing to understand about homeschoolers is we are all networked," said Ken Cuccinelli, a member of Homeschoolers for Cruz and an occasional campaign surrogate.

He said the group has used email pleas, door-knocking, and old-fashioned word-of-mouth to win votes. "The real rock stars are the teenagers. They have so much energy... And work ethic. They just churn through work like us old people don't."

Cruz's campaign is betting that support like that will help him secure a win in Texas - the biggest prize among the 12 states holding Republican nominating contests on Super Tuesday.

Texas has 155 delegates and a big win for Cruz could potentially shift the balance of the race to decide who will be the Republican nominee at the Nov. 8 presidential election. Trump currently has 82 delegates to Cruz's 17.

Only around 3.5 percent of schoolchildren in the United States are homeschooled. But the families that endorse homeschooling can have outsized political influence in some states and are often conservative.

Many proponents of homeschooling share two important traits: a bent toward religion and a tendency to carefully guard against education policy changes that could affect them personally.

"(Cruz) is going to make sure that the federal government will not infringe on what we believe is our God-given right," said Will Estrada, a Virginia-based co-chair ofHomeschoolers for Cruz and a lawyer at the Home School Legal Defense Association - which does not typically endorse candidates before the general election.

Cruz leads Texas

Homeschoolers help candidates tap into the evangelical vote, long thought to be Cruz's firewall in Southern states, even though he has struggled to win the conservative Christian vote amid the challenge by Trump.

Cruz leads Trump in Texas, 36.2 to 26.6 percent, according to a RealClearPolitics poll average, one of few leads predicted for the Texas senator for March 1 contests.

The stakes are high for Cruz on Tuesday. At a recent presidential forum at Regent University in Virginia, also a Super Tuesday state, Cruz warned that a runaway victory for Trump could make the billionaire businessman “unstoppable."

Marlin Bontrager, a homeschooler parent whose family gospel band tours the country by bus, said he's supporting Cruz in part because he worries that secular education has contributed to a drop in the American intellect and the rise of Trump, as well.

"Our educational system has(...) dumbed down our society. And we're seeing the effect of that this election," he said, referring to the broad support for Trump.

In 2008, homeschoolers in Iowa mobilized around then-Republican presidential hopeful Mike Huckabee, helping him win the state.