"The naysayers, including some in my party, I'm sorry to say, say I cannot win, and I say to heck with that. I'm taking my case directly to the people," said Van Os, who is running against incumbent Republican Attorney General Greg Abbott.
Van Os said that as the business interests give more money to political campaigns, politicians have developed a culture of greed and corruption.
He talked about the rising cost of gas in Texas, attributing the increase to the recent mergers of some of the major fuel companies such as Chevron and Shell, He said many elderly and low-income residents can no longer afford gas.
"Working people are having to choose not being able to afford not going to work or not being able to afford going to work," Van Os said.
After his speech ended, Van Os' wife Rachel Barrios-Van Os told a story about an elderly man who came to Van Os in Caldwell County, crying because he and others in his community couldn't afford gas.
"He said to David, 'Will you fight for us,' " Barrios-Van Os said. "People are crying, democracy is being stolen in front of our very eyes and they see it," she added.
Van Os also lamented that many victims of Hurricane Rita could not afford homeowners insurance and have not been able to fix their damaged homes.
Van Os said that Texans pay the highest premiums on homeowners insurance in the country because of what he called corporate control over those who set the premium rates. Texas Department of Insurance spokesperson Jim Hurley confirmed that Texans pay higher rates but said it is because Texans file more claims than people in any other state because of hurricanes, hail, tornadoes and other natural disasters.
The attorney general's office has the authority to protect consumers and can sue gasoline, insurance and other types of companies.
Van Os added that Abbott receives money for his campaign from corporate interests, citing Houston home builder Bob Perry, who has contributed $1.1 million. Van Os said home building is another industry in Texas with too few companies for consumers to choose from.
Jim Mattox, former Democratic attorney general for Texas from 1983-1991, said that Van Os faces a difficult time getting his name out, though he thinks Democrats may be able to exploit Gov. Rick Perry's low approval ratings.
"I would tell him to try to get all the Democratic ticket to campaign together and to continue to preach fire and brimstone in the media. David is a great speaker; he is probably the best speaker running today in Texas politics," Mattox said.