Angie Chen Button won an expensive and bruising contest over Randy Dunning in the Republican primary race to succeed retiring state Rep. Fred Hill.

Ms. Button, 54, and Mr. Dunning, 50, both Garland residents, spent the month-long campaign lobbing a nearly constant barrage of attacks and spending roughly $600,000.

Each said the charges lobbed by the opposition were baseless attacks. At the same time, they said their accusations — that Ms. Button has shown a lack of commitment to the GOP and that Mr. Dunning had exhibited questionable behavior — were worth noting.

Ms. Button said the high cost — she spent more than $300,000 of her own money — was worth it.

She said she hoped Mr. Dunning and his supporters would back her come November.

“I believe fellow Republicans should help each other out,” the marketing executive and Dallas Area Rapid Transit board member said. “The general election will be tough in Dallas County.”

The Republican nominee will face Democrat Sandra VuLe and Libertarian Philip M. White in November.

During the campaign, Ms. Button said her decades of networking with North Texas community leaders and service on various regional boards and chambers of commerce gave her a base on which she could build consensus and devise better solutions to regional issues.

But while she identified several primary issues — property appraisal reform and transportation funding, for example — she took few firm positions on how she would address them.

Meanwhile, Mr. Dunning touted his years of service to the Republican Party.

The software engineer and former Garland City Council member has served on the party’s state platform committee, experience that he said gave him deep familiarity with the party’s principles.

Also, he said, serving as an elected official in Garland gave him stronger experience in representing constituents than Ms. Button’s years as an appointed member of the DART board.