GEORGETOWN – The conversation unfolding before a campaign event for U.S. Sen. Ted Cruz here last week echoed similar ones popping up among Republican groups around Texas. With a mixture of frustration and bewilderment, attendees were discussing the proliferation of black-and-white yard signs in their neighborhoods brandishing a single four-letter word: BETO.

The signs have become a signature calling card of Democrat Beto O'Rourke's bid to unseat Cruz. While Democrats posting yard signs for candidates is nothing new, even when it happens in some of Texas' most conservative enclaves, what's been different this summer is the extent to which O'Rourke's signs have seemingly dominated the landscape in some neighborhoods.

Meanwhile, Cruz signs are far tougher to spot, and many Cruz supporters have become increasingly agitated by their inability to obtain signs to counter what they see on their daily drives.

Once the event in Georgetown got started, one of the earlier speakers — a candidate for county office — jokingly pleaded with the crowd to quit asking him for Cruz signs because he could not provide them.

Cruz later fielded a question about signs from the local member of the State Republican Executive Committee, Mike McCloskey.

"The one question I get asked universally, everywhere is, 'We’re seeing signs that say 'Robert Francis' in our neighbors’ yards, and we want to claim our territory and have your signs in our yards,'" McCloskey told Cruz, using O'Rourke's birth name. "I think people here are wanting those. What can we do to get those in the hands of the folks that want to have them in their yard?"

"That’s a question we hear a lot," Cruz said. "Yes, there are a lot of signs for my opponent, Beto O’Rourke. They invested a ton of money and they put that money, part of it, into having signs everywhere."

The sign disparity is not necessarily indicative of an enthusiasm gap, but of differences in campaign spending priorities. But more broadly, Cruz campaign manager Jeff Roe has an aversion to yard signs — he said he views them as a far-less-effective use of campaign money than door knocking, television and radio advertising, phone banking or direct mail. That's not a new strategy in Cruz world. Roe said the Cruz 2016 presidential campaign spent no money on yard signs.

"It would be an easier campaign to win if we just used yard signs, and whoever wins is who puts up the most yard signs," Roe told The Texas Tribune.

Even so, the Cruz campaign has distributed 10,000 signs so far, and ordered another 25,000 for these anxious supporters.

On Tuesday afternoon, the Cruz campaign sent out an email to supporters with the subject line, "Yard Signs are Here – Get Yours!" The signs are available on its website for $10 – the same price O'Rourke is selling signs on his own site. Both campaigns also offer sets of 100 or more at discounted rates.

"We respect and admire the contributions of our volunteers and the people coming to the rallies for the senator and admire their participation in the process," Roe said. "They said loud and clear they would like those signs, and we are happy to oblige while maintaining the efficient and effective voter campaign while being outspent."

So how many O'Rourke yard signs are there actually around Texas? An O'Rourke spokesman said the campaign has not tracked the number of signs they've sold or given away.

Texas hasn't elected a Democrat statewide in over 20 years. But recent polls show the race between Cruz and O'Rourke within single digits. O'Rourke has also taken the lead in fundraising.

While the paucity of Cruz signs does not appear to reflect a lack of enthusiasm on the Republican side of the race, the decision has nonetheless begun to have a psychological impact in some communities, energizing O'Rourke backers and, at the very least, unnerving some Cruz voters.

The topic has come up repeatedly at Republican gatherings in recent weeks. On a telephone town hall Cruz held with supporters earlier this month, one caller introduced himself as an Uber driver from Keller who said he travels "all over the Mid-Cities and Tarrant County and whatnot, and Beto signs are everywhere." The man told Cruz he has "not seen one sign for you other than the one that's on my back patio." He asked whether the lack of signs was due to the Cruz campaign taking Republican-leaning Tarrant County for granted, or whether the campaign simply lacked the money to offer its supporters signs.

"I hear that all across the state, and there are a lot of Beto O'Rourke signs that are out there," Cruz replied. "And the reason is they invested big, big dollars early on."

Cruz went on to recall his "famously cheap" campaign for U.S. Senate in 2012 – one in which he defeated Lt. Gov. David Dewhurst, who put millions of dollars of his own money into the race and was widely viewed as the frontrunner until Cruz's upstart bid gained traction. "We watch our pennies very, very closely," Cruz told the man, saying supporters were similarly frustrated six years ago with the availability of yard signs, but that was "because we were saving our money to use it when it has the greatest effect.”

Last week, at a GOP gathering in Salado, a small, community halfway between Waco and Austin, attendees distributed a bulletin that highlighted all the O'Rourke signs popping up in conservative neighborhoods. A speaker urged patience among local Republicans on the lack of Cruz signs, telling the relieved crowd that she was working with a local printer on getting legal clearance to print their own local Cruz campaign signs and that the campaign would purchase more signs in the coming weeks.

It was a very different scene at an O'Rourke rally in Fort Worth over the weekend, in which staffers and volunteers put together signs with assembly-line speed and happily distributed them. When asked how many signs they had given out that evening, the O’Rourke staffers shrugged, a nod to how difficult it was to keep track.

O'Rourke told the Tribune Tuesday that the signs have helped boost his campaign's reach — particularly in more conservative communities.

“We go to a town hall in Waco, or we were in Huntsville the day before yesterday, and folks are hopeful — and I’m in turn hopeful — they say, ‘Hey, there are yard signs all over the place in neighborhoods that I never would’ve expected to see one. That gave me some courage to come out to this town hall or to get a yard sign myself,'" O'Rourke said. "'Now I know it’s OK in this suburb of Houston or this stretch of West Texas to be for you or to be with other people who think the way that I do.’ It’s been a real surprise for us, but a positive one."

The congressman echoed Cruz's campaign manager in asserting that door knocking and candidate appearances are a more effective means of campaigning, but he insisted signs matter as personal endorsements.

"The more human, the more powerful it is," he said. "But literally planting that sign ... you’re personally and powerfully saying, 'Look, I’m part of this amazing thing that’s going on in Texas right now.' That’s really powerful.'"

The difference in tactics goes back to a 2006 political science experiment. At the time, former Gov. Rick Perry was running for his second full term and allowed for researchers to try different tactics in some communities to test which were most effective at motivating voters. Daron Shaw, a government professor at the University of Texas at Austin and co-director of the Texas Tribune/University of Texas Poll, worked on experiments involving yard signs in Perry’s race and saw little evidence that they moved Perry's numbers.

Four years later, Perry’s team essentially abandoned the entire practice of distributing yard signs during his third re-election campaign. He soundly defeated now-former U.S. Sen. Kay Bailey Hutchison in the Republican primary and Democrat Bill White in the general election.

Since then, more academic research backed up Shaw's findings, and yard signs have largely fallen out of vogue within the Texas GOP consultant class, at least among statewide candidates.

But that 2006 campaign marked Perry’s fifth statewide race — when he already had near-universal name identification in Texas, much like Cruz does now. As such, Shaw cautions not every campaign should follow Perry’s lead.

“It varies race by race and year by year," he said. "So I wouldn’t claim that that study should be used as evidence that you ought not to be doing it this time around."

For a candidate like O’Rourke, who began the race as a relative unknown, there is anecdotal evidence that the signs have helped him build his name identification.

Jo Johns is a retired physical education teacher who recently attended an organizing rally for O’Rourke in Weatherford.

She told the Tribune she first learned about O'Rourke by seeing his signs while driving to yoga class.

“I didn’t know who he was, and I wanted to know about him,” she added. “I saw Beto, Beto, Beto. I thought he must be a Republican because they’re everywhere.”

Shaw pointed back to the 2014 governor's race, when Democrat Wendy Davis' signs outnumbered her opponent, now-Gov. Greg Abbott, in some communities. Davis still lost by 20 points. But this time around, the political scientist suggests O'Rourke's yard signs are possibly signaling momentum to voters, priming some who may have otherwise assumed Cruz was unbeatable that O'Rourke has a shot.

“In this race, it probably is more of a positive because it reinforces information you’re getting in public polls, stories you’re getting in the media and fundraising," said Shaw.

Roe and the Cruz campaign intend to continue to prioritize other ways of getting out the vote.

"At the end of the day," Roe said, "our campaign will be measured by one thing and one thing only: Whether we win the race."

Disclosure: The University of Texas has been a financial supporter of The Texas Tribune, a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune's journalism. Find a complete list of them here.