WASHINGTON – There are early signs of Democratic enthusiasm in Texas in the latest round of federal campaign finance report filings over the weekend, but whether that fundraising support will translate into trouble for Republicans remains to be seen.

Four GOP incumbents from Texas – U.S. Sen. Ted Cruz, and U.S. Reps. John Culberson of Houston, Ted Poe of Humble and Lamar Smith of San Antonio – found in recent days that their Democratic challengers had posted better fundraising hauls than they had in the second quarter of this year.

"It's happening in other places as well," said Achim Bergmann, a Democratic consultant who has clients across the country including one challenging Culberson. "It's particularly surprising and encouraging in a place like Texas, and it might be an indication of where Republicans are taking things for granted and are going to be sorry."

This sort of scenario is the first sign of incumbent danger in political circles, but most of these incumbents already have hefty war chests from previous campaigns.

"Comparing a quarter's worth of fundraising is like declaring victory after one inning of a baseball game," cautioned Nathan Gonzales, a political analyst at Inside Campaigns, a political newsletter.

The most recent fundraising stretch – early April through the end of June – marked a time when dozens of Democratic challengers declared their campaigns for office around the state. The Democrats highlighted below either out-paced – or nearly out-paced – their Republican rivals in the second quarter.

U.S. Senate

U.S. Rep. Beto O'Rourke, D-El Paso, posted a $2.1 million quarterly haul in his first report since launching a bid to unseat Cruz, who raised $1.6 million. But Cruz had a $3.8 million cash-on-hand advantage at the end of the quarter and is likely to have major national party and superPAC support.

U.S. House races:

Texas' 2nd District: Poe's quarterly haul was on the small side – $81,000 – but he had about $2.1 million in cash on hand, a staggering financial starting point for any House incumbent. A number of Democrats are running against him, but nonprofit executive Todd Litton outpaced him with $139,000 raised. He has $132,000 in cash on hand. Neither Gonzales' Inside Campaigns nor the Cook Political Report, another political journal, has rated the district as competitive.

Poe's quarterly haul was on the small side – $81,000 – but he had about $2.1 million in cash on hand, a staggering financial starting point for any House incumbent. A number of Democrats are running against him, but nonprofit executive Todd Litton outpaced him with $139,000 raised. He has $132,000 in cash on hand. Neither Gonzales' Inside Campaigns nor the Cook Political Report, another political journal, has rated the district as competitive. Texas' 7th District: Culberson, who has never been among Congress' strongest fundraisers, heeded Democratic threats to his district and raised a larger-than-usual $336,000 this quarter and reported $361,000 in cash on hand. Even so, two Democrats among a crowded field raised more than he did. Nonprofit executive Alex Triantaphyllis had the best quarter of any House challenger in the state, with $451,000 raised and $402,000 in cash on hand. But attorney Lizzie Pannill Fletcher also posted a healthy quarter, with $366,000 raised and $343,000 in cash on hand. Her finance report featured two Democratic notables: Mark White III, the son of former Texas Gov. Mark White; and U.S. Sen. Kirsten Gillibrand of New York, who keeps an eye out for female candidates to support. As a member of the U.S. House Appropriations Committee, Culberson should have the legislative leverage to keep pace with any Democratic rival.

Culberson, who has never been among Congress' strongest fundraisers, heeded Democratic threats to his district and raised a larger-than-usual $336,000 this quarter and reported $361,000 in cash on hand. Even so, two Democrats among a crowded field raised more than he did. Nonprofit executive Alex Triantaphyllis had the best quarter of any House challenger in the state, with $451,000 raised and $402,000 in cash on hand. But attorney Lizzie Pannill Fletcher also posted a healthy quarter, with $366,000 raised and $343,000 in cash on hand. Her finance report featured two Democratic notables: Mark White III, the son of former Texas Gov. Mark White; and U.S. Sen. Kirsten Gillibrand of New York, who keeps an eye out for female candidates to support. As a member of the U.S. House Appropriations Committee, Culberson should have the legislative leverage to keep pace with any Democratic rival. Texas' 21st District: Smith stayed within his normal quarterly range, with $198,000 raised. Veteran Joe Kopser narrowly raised more – $205,000 – but Smith outpaced him by about $700,000 in cash on hand. Neither Gonzales nor Cook rate this seat as competitive at this point, but the district has seen a flood of Democratic candidates. Party insiders in Washington are closely watching this race as a potential opportunity if a major wave takes shape.

While ads from super PACs have often dominated the television airwaves ahead of elections in recent years, candidate fundraising still matters because it illustrates enthusiasm — and candidates are able to book TV ads at a lower price than outside groups.

Bragging rights are due for any challenger who raises more than an incumbent – many donors refuse to give to challengers. But the first quarter is often among a candidate's strongest; it's the low-hanging fruit and easiest ask.

Additionally, some of this money will be spent by Democrats to survive their own primaries. The Houston-based Democratic primary for Culberson's seat has the potential to turn into a financial arms race, with Democratic candidates spending hundreds of thousands to make it through both a primary election and expected runoff.

While some GOP incumbents may have posted comparatively weak second quarters, months and years of previous fundraising keep them on strong footing going forward.

"These Democrats are off to a great start, but this is a long game, and most of them will have to do even better," said Gonzales.

Other noteworthy fundraising:

Texas' 32nd District: U.S. Rep. Pete Sessions, R-Dallas, is, much like Culberson, a new Democratic target. Former Secretary of State Hillary Clinton carried both of their districts in 2016 and Democrats are challenging both incumbents for the first time in years. Both primaries are crowded. Sessions outraised all of his rivals with a $ 399,000 haul, but former Clinton staffer Ed Meier came within spitting distance, with $344,000 . Sessions, who formerly ran the national House GOP campaigns, has a fearsome $903,000 in cash on hand.

U.S. Rep. Pete Sessions, R-Dallas, is, much like Culberson, a new Democratic target. Former Secretary of State Hillary Clinton carried both of their districts in 2016 and Democrats are challenging both incumbents for the first time in years. Both primaries are crowded. Sessions outraised all of his rivals with a $ haul, but former Clinton staffer Ed Meier came within spitting distance, with . Sessions, who formerly ran the national House GOP campaigns, has a fearsome Meier, who has $ 298,000 in cash on hand, reported personal donations from multiple top officials from Clinton's world, the Obama administration and current and former officeholders: Washington attorney Robert B. Barnett, Georgetown professor Peter Edelman, former Biden chief of staff Ron Klain, former Treasury Secretary Jack Lew, former campaign manager Robby Mook, longtime Clinton loyalist Minyon Moore, former Clinton campaign chairman John Podesta, former Clinton spokesman Philippe Reines, former U.S. Sen. Ken Salazar of Colorado, Clinton adviser Jake Sullivan, former Clinton aide Neera Tanden, former U.S. Rep. Ellen Tauscher of California and the leadership PAC of U.S. Sen. Mark Warner.

personal donations from multiple top officials from Clinton's world, the Obama administration and current and former officeholders: Washington attorney Texas' 8th District: U.S. Rep. Kevin Brady of The Woodlands raised a monster $ 842,000, with nearly $2.5 million in cash on hand. Many Texas Republicans anticipate he will face a primary challenge from the right. But as chairman of the U.S. House Ways and Means Committee, Brady is at the center of major policy debates and is, as a result, a magnet for money.

U.S. Rep. Kevin Brady of The Woodlands raised a monster $ Many Texas Republicans anticipate he will face a primary challenge from the right. But as chairman of the U.S. House Ways and Means Committee, Brady is at the center of major policy debates and is, as a result, a magnet for money. Texas' 23rd District: U.S. Rep. Will Hurd, a Helotes Republican, holds the the most competitive seat in the state. Democrats have yet to announce a serious challenger for 2018, though former U.S. Rep. Pete Gallego, Democrat of Alpine, has said he's considering running again against the man who has defeated him twice. Hurd spent the first half of the year building up his cash-on-hand sum to $736,000.

Disclosure: Joseph Kopser has been a financial supporter of The Texas Tribune. A complete list of Tribune donors and sponsors can be viewed here.