TOPEKA, Kan. — Democratic gubernatorial candidate Paul Davis on Tuesday introduced Jill Docking as his running mate, making taxes and education spending the focus of their 2014 campaign.

Docking, a 57-year-old investment adviser from Wichita whose husband was lieutenant governor in the 1980s, said she and Davis shared a "grave concern" over the lack of funding for public schools.

"It is the reason for this partnership and I think it will be a strong partnership. Because we have many, most of the same values," she said at Highland Park High School during the Topeka stop of a four-city bus tour with Davis.

"She understands that a good public education system is really the key to economic success," Davis said of Docking, who served on the Kansas Board of Regents from 2007 to 2010.

In 1996, she was Republican Gov. Sam Brownback's opponent for the U.S. Senate, garnering 43 percent of the vote to Brownback's 54 percent. Her husband, Tom, is a former lieutenant governor and he's the son and grandson of Kansas governors.

Brownback, who is yet to formally announce his re-election campaign, won his first term as governor in 2010. Docking ruled out her own run at governor this summer, saying she didn't know what her political future held.

Kansas GOP Chairman Kelly Arnold said Democrats were "doubling down" on President Obama's agenda by placing two delegates to the Democratic national convention at the top of their ticket.

Davis, 41, is the Kansas House minority leader. He announced that he was seeking his party's nomination for the gubernatorial ticket in September — his first bid at statewide election.

He and Docking criticized Brownback's cuts to income tax cuts enacted in 2012, saying the higher sales and property taxes put too much of a burden on the middle class.

"When you're in a hole, the first thing that you do is you stop digging. You cannot go farther in terms of income tax cuts that this state simply cannot afford," Davis said.

Kansas Republican Party Executive Director Clay Barker said legislators had to focus on all areas of government, not just education, when setting spending priorities.

"I think there is a difference in pushing for stronger and quality education versus just pushing for more money. Money is a component of that but it's not the only component," Barker said.

Docking's addition to the Davis team will help give the Democratic ticket name recognition, which should help in fundraising efforts. Barker noted that no Docking has won an election in Kansas in more than 30 years.

Brownback began 2013 with more than $518,000 in campaign funds, and Democrats concede he's likely to have plenty of money for a re-election bid. Brownback raised almost $3.1 million for his successful 2010 campaign, almost half of it in 2009.