Jason Holsman says his six years in the Missouri House prove he can steer progressive legislation to success in a Republican-dominated General Assembly.

Crystal Williams says her two decades as a nonprofit advocate demonstrate she is dedicated to being a champion for progressive causes.

And both believe the other is a bad fit to be Kansas City's next state senator.

The two Kansas City Democrats are battling in the Aug. 7 primary to take over for Sen. Jolie Justus and represent the 7th District in the Missouri Senate.

But there are few differences on issues.

Both support abortion rights. Both support expanding Medicaid as called for in President Barack Obama's health care law. Both agree any plan to improve the state's failing public schools must include a focus on such issues as poverty and neighborhood crime. And both decry the legislative priorities of the Missouri GOP.

But each views the other's qualifications to fight for those policies in Jefferson City with skepticism.

Williams, 50, says Holsman has an "uncanny instinct for cozying up to Republicans."

Holsman, 36, calls Williams a "hyperpartisan who will try to be an obstructionist" in the Senate.

The district -- which encompasses downtown and parts of midtown, Grandview and Lee's Summit -- is considered one of the most liberal in the state. So it's no surprise the two are fighting for the title of most progressive candidate, said Justus, who because of redistricting will spend her final two years in the Senate representing a district in eastern Missouri.

Holsman is a faculty member of the University of Phoenix and a former Kansas City Public Schools teacher. While serving in a Democratic minority, he successfully won passage of numerous bills, most notably one allowing customers who generate their own electricity to be allotted renewable energy credits from their utility.

His advocacy for environmental issues eventually won him appointments by GOP House Speaker Steve Tilley to chair committees focusing on renewable energy and urban agriculture.

"I have always been a progressive legislator, but I know how to play well with others," Holsman said.

Williams has worked as a lobbyist and advocate for groups such as Planned Parenthood and Partnership for Children. In that role, she helped fight to establish the state's first family planning funding and said she "worked tirelessly to protect women's right to choose."

"I bring decades of policy experience to the table working on progressive issues," Williams said. "I know how important it is to work across the aisle with my colleagues in the Republican Party, but it is highly unlikely that they are going to be giving me a chairmanship, let alone two."

Holsman dismisses his rival's criticism of being appointed to lead committees by Republicans as a "Karl Rove tactic to use someone's success against them."

"I have been an effective member of the minority," he said. "I've overachieved given the political circumstances. I make no apologies for that."

Only three other Democrats chair committees in the Missouri House.

To defend his progressive record, Holsman points to criticism from his 2010 GOP opponent, who consistently referred to him as "one of the most leftist legislators in Missouri."

But trying to paint her as an obstructionist shows Holsman doesn't understand the voters in the district, Williams said.

"We want positive, productive policy that supports jobs, education and economic development," she said. "But we also want our senator to obstruct legislation that would limit health care access for women and their families, or legislation that spews hate for our LGBT or Hispanic neighbors."

Williams says the record is clear. Before he knew he was running this year for a seat in the Senate, she says, Holsman made a number of bad votes on key issues. Specifically, she points to his support in 2008 for legislation that, among other things, prohibited the state from issuing driver's licenses to undocumented immigrants and curtailed the creation of sanctuary cities.

Holsman also voted "present" on two pieces of legislation last year that placed new restrictions and penalties on doctors performing late-term abortions. Seventeen Democrats supported the bill and 33 voted against it. Holsman was the only member of either party to vote "present."

Holsman said he voted for the immigration bill because it also included workplace safety measures that were a priority of organized labor organizations. Only 11 House Democrats voted against that bill.

His votes on last year's abortion bills were an attempt to make a statement that "this legislation should not be decided by men," he said. He previously voted against the bills.

Because Williams is "unaccomplished, she has to find things to try to tear me down," Holsman said.

Justus predicted that the winner of the primary will come down to who works harder at getting their message out to voters.

"In this district, you have to get out there and knock on doors," said Justus, who is staying neutral in the primary. "Right now, I honestly can't tell who is going to win. It appears to me that they are neck and neck."

The winner will be unopposed in the November election.