AUSTIN, Texas (Reuters) - In one of the country's most conservative states, newly hopeful Democrats measure their progress by ringing a bell.
For those working to turn Texas from Republican red to Democratic blue, it's the sound of one more volunteer agreeing to join their ranks. On a recent Saturday, phone-bank volunteers in a modest office here smacked the bell every five minutes or so, adding to the nearly 12,000 who have joined the effort.
In the past year, alumni from Democratic President Barack Obama's 2012 campaign quietly have built a grassroots army in Texas, where gun-rights advocates brandish semi-automatic rifles on city streets and pickup trucks bear "SECEDE" bumper stickers.
Battleground Texas, as the group is known, is backing Democratic state Senator Wendy Davis' underdog bid for governor this November against Republican Greg Abbott, the state's attorney general.
But those involved say their larger goal - likely to take years to realize, if ever - is to make Texas as competitive in national elections as politically divided states such as Virginia and Ohio. That means identifying potentially Democratic voters, namely those in the state's booming Hispanic population, and persuading them to show up at the polls.
It is an unusually ambitious effort in U.S. politics. National parties typically measure progress in two- and four-year election cycles, with less focus on longer-term operations.
If Democrats succeed, they could upend the state's low-tax, low-regulation approach to governance and give their party a decisive advantage in presidential elections for years to come.
Battleground Texas faces a steep climb, however.
Democrats have not won a statewide race in Texas for nearly 20 years, and the party now has trouble fielding candidates for many congressional, state and local races.
They also face procedural barriers that they say can make it tougher to register voters than in many other states, and often discourage minorities and low-income residents from participating. Those include a new law that requires residents to show state-issued photo IDs to vote.
But the group has two factors on its side: the state's growing Hispanic population, which has favored the Democratic Party over Republicans by a 19-point margin in recent polls, and the meticulous door-to-door organizing techniques honed nationwide during Obama's two presidential campaigns.
The campaigns' on-the-ground organizing helped to give Democrats an edge over Republicans in voter data that the Texas group seeks to exploit by targeting many of the 10.5 million eligible Texans who did not vote in the 2010 governor's race.
Turnout analysts say that Hispanics made up a disproportionate share of those who stayed home that year. Democrats also see opportunities to win over suburban white women who may feel alienated by the Republican Party's rightward drift and support of cuts in education.
"There's a huge amount of potential there," said Jeremy Bird, who launched the Battleground Texas effort after working as Obama's national field director in 2012.
Republicans acknowledge they need to do more to reach out to Hispanics and other minority groups. But so far, they see little evidence that Democrats are gaining ground in Texas, even as Davis' campaign for governor is drawing interest, and millions of dollars in donations, from across the nation.
"All this work and all this money that they've spent up to now so far is not showing results," Texas Republican Party Chairman Steve Munisteri said.
Democrats face long odds this year and probably won't carry the state in the next presidential election in 2016, said James Henson, who heads the nonpartisan Texas Politics Project at the University of Texas.
But by 2020, the state's Hispanic population is projected to eclipse its white population, and Democrats could make Texas competitive, he said.
"Certainly in 2014 everybody will be looking to see if there's a leading edge of something bigger coming," Henson said.
Republicans say they recognize the challenge and have assigned seven staffers to reach out to Hispanics.
But there have been signs that Republican candidates may be undermining that effort as they court conservative voters ahead of the March 4 party primaries.
Abbott drew criticism from Hispanic groups and others this month when he said corruption in Texas' mostly Hispanic Rio Grande valley resembled "Third World country practices."
He also came under fire for campaigning with 1970s rocker Ted Nugent, who called Obama a "subhuman mongrel." Nugent later apologized.
Another Republican, in a four-way primary race for lieutenant governor, has said undocumented Hispanics represent an "illegal invasion" of the United States.
Few prominent Texas Republicans back the immigration overhaul that passed the Democratic-led U.S. Senate last year, a top priority of Hispanic groups.
The Texas Republican Party's official platform takes a hard line on immigration, saying that U.S. citizenship should be limited to those with at least one parent who is already a citizen. That could exclude from citizenship the party's own director of Hispanic outreach, who was born to Mexican parents.
"It's not a deal breaker for me," said director David Zapata. When promoting Republicans' ideas to fellow Hispanics, he emphasizes job creation and school choice rather than immigration.
Democrats, who dominated Texas politics for decades until the early 1980s, only recently began to rebuild in the state.
Republicans are unchallenged in seven of the state's 34 congressional seats and 60 of the 150 state House of Representatives districts this year. In suburban Denton County, north of Dallas, Democrats have no candidates for district attorney, county judge and other important local posts.
It's a chicken-and-egg problem, said Jenn Brown, Battleground Texas' executive director.
"Volunteers don't like working for bad candidates, but good candidates don't want to run unless they feel there's an infrastructure there to support them. So we decided to just go and start building," she said.
A veteran of both Obama campaigns, Brown set up a neighborhood-based approach that encourages volunteers to organize phone calls and track voter responses.
Having Davis at the top of the ticket has helped, Democrats say. She was popular among Texas Democrats even before her unsuccessful 11-hour filibuster against proposed abortion restrictions rocketed her to national fame last June.
Davis' campaign and Battleground Texas together have raised nearly $16 million since July 2013. The two groups have $11.3 million in the bank, about one-third of Abbott's war chest.
But Davis is losing ground in polls. A Texas Tribune/University of Texas survey this week had her trailing Abbott by 11 percentage points. She trailed by 6 points in October.
Battleground Texas' tactics have come under attack by conservative provocateur James O'Keefe, whose undercover videos brought down the liberal group ACORN.
O'Keefe released a video last week showing Battleground volunteers copying phone numbers from voter-registration forms they had collected from residents, which Republicans say violated state law.
Brown said it was legal, but added that Battleground had discontinued the practice before the video came out.
"We decided to change it because the law was unclear and we knew attacks would be coming at some point," she said.
The episode reflects some of the legal hurdles Battleground faces. Besides the new law requiring voters to show a photo ID at the polls, Texas requires any individual who wishes to register new voters to get certification.
That doesn't seem to deter the volunteers.
Between calls in Battleground's office in Austin, University of Texas student Chris Cyrus said he and other volunteers recently registered 80 new voters in one day on campus. Cyrus, 21, said Democrats aren't as rare in Texas as he once thought.
"It really seems like it's something that's kicking up this election cycle in a way I've not seen before," he said.
Editing by David Lindsey and Ross Colvin