Demographic shifts, energized straight-party voters and coordinated campaigns culminated in success for most Democratic state House candidates in Dallas County.

And several Republicans who won Tuesday should expect to be targeted in 2010 as Democrats work toward long-term dominance here.

"We'll go back and look at the numbers and see what we can work on," said Darlene Ewing, Dallas County Democratic Party chairwoman. "It started in 2002 when we got one judge elected. It picked up in 2004, and in '06 it accelerated probably faster than we thought."

This year, the Democratic wave included wins by Robert Miklos and Carol Kent. Kirk England, who was first elected as a Republican but changed parties in 2007, held on to his Grand Prairie-area seat.

In Irving, with about 280 provisional ballots yet to be counted and a recount looming, Republican Linda Harper-Brown is clinging to a lead against Democrat Bob Romano.

The Democratic gains came amid a pricey last-minute push from Republicans. Ms. Harper-Brown took in $10,000 from House Speaker Tom Craddick's Stars Over Texas PAC in the last week. Meanwhile, the Republican Party of Texas spent more than $95,000 on television ads and mailers for Karen Wiegman, Mr. England's opponent.

"Dallas County is a Democratic county," said Cal Jillson, a political science professor at Southern Methodist University. "The inner-ring suburbs, those are the ones that are turning over, particularly when you have a weak incumbent."

Dr. Jillson said Republican Dan Branch of University Park should be safe in District 108, which also includes Old East Dallas, downtown, Uptown and parts of Oak Lawn. But that doesn't stop Ms. Ewing from including Mr. Branch in her list of potential targets. "You've got a real solid core of Republicans," she said. "But you look out on the edges of the district, and there are opportunities."

Democratic strategists saw opportunity in District 102, a North Dallas-Lake Highlands-Garland district held by Republican Tony Goolsby, and in District 101, a Mesquite-Sunnyvale district.

Ms. Ewing said the party focused on reliable Democrats, allowing candidates to knock on doors and speak with potential crossover voters. Mr. Miklos credited one-on-one time with voters for his win over Mr. Anderson in District 101.

But Mr. Branch noted that he swayed many who voted for Barack Obama. While John McCain won about half the vote in District 108, Mr. Branch coasted to victory with nearly 61 percent.

"Texas is a center-right, limited-government state," Mr. Branch said. "The larger message for us is, people don't want conservatism that's limited to rhetoric. If government's going to be in the space, it had better be effective."

For candidates in the party that is losing power, a connection to constituents is key, Dr. Jillson said. Mr. England said that's why he switched parties – the Republicans weren't working in the interests of urban and suburban districts.

"The Republican leadership has absolutely lost touch with things that are good for Texans," said Mr. England, who barely won in 2006 but easily bested his opponents Tuesday. "I think I've got a good feeling for districts like mine."

Meanwhile, Republicans held off Democrats in two eastern districts. Joe Driver of Garland survived a challenge in District 113. And Republicans held on to the District 112 seat, with Angie Chen Button of Garland elected to replace the retiring Fred Hill.

So how did Ms. Kent, a Democrat, win District 102, while Republican Ms. Button took the neighboring district? Demographics and resources.

"I don't think we could have done anything better," said Sandra Phuong VuLe, Ms. Button's Democratic opponent. "I think we really did get all the Democrats out to vote. We really had to get out there and convert the independents and Republican voters in the district."

Ms. Ewing credited Ms. VuLe for a strong volunteer-driven effort, but said the resources – paid, professional campaign management, for instance – were not there to overcome the conservative tilt in District 112.

Mr. Driver said he worked to ensure re-election. He conducted polling for the first time in years, which helped him to gauge where to focus time and money.

Dallas County Democrats' successes have also spilled over into Tarrant County, where two Republican incumbent legislators lost Tuesday.

Allan Saxe, an associate professor of political science at the University of Texas at Arlington, said Tarrant County is still a Republican stronghold. Dr. Saxe said straight-party voting, along with Mr. Obama's momentum, helped fuel the Democratic wins.

Jeff Dalton, who directed Dallas County's Democratic campaign, said straight-party voting was part of the strategy. But the number of straight-party votes and the early-voting turnout for Democrats exceeded even his expectations.

Ms. Ewing said the hope is to build upon 2008, even when there isn't a powerful driver such as Mr. Obama.

"We didn't have a president at the top of the ticket in '06," she said. "What also energizes your faithful is winning. Our people have been thirsty for this since the '80s."

Staff writer Frank Trejo contributed to this report.