DES MOINES, Iowa (AP) — The two Democrats vying to be Iowa's next U.S. senator each tried to explain in a debate Thursday why he's the one to flip the Republican-held seat, showcasing a struggle within the party over the best strategy to reclaim the U.S. Senate this fall.

State Rep. Josh Turek said he's the “battle-tested” candidate who has won in his red state House district, outperforming President Donald Trump by reaching independents and moderate Republicans. State Sen. Zach Wahls criticized national Democratic leaders, including Sen. Chuck Schumer, who he says have written off and lost the trust of rural and working-class voters who are frustrated with both parties.

The two spent a largely cordial hour showing many areas of agreement, but an influx of outside spending and recent big-name endorsements has intensified one of the few remaining competitive Democratic Senate primaries this year. Both Democrats directed most of their attacks toward Rep. Ashley Hinson, who is seeking the GOP nomination.

Iowa’s Republican Sen. Joni Ernst opted out of a reelection bid, leaving the seat open for the first time since she replaced retiring Democratic Sen. Tom Harkin in 2014. Republican Senate leaders have backed Hinson, who represents northeast Iowa, and the campaign arm has committed $29 million to help her keep their thin majority.

Democrats see an opportunity to flip seats in the once-competitive state, despite Trump’s double-digit win in the last presidential election and an all-Republican federal delegation. The political committee aligned with Senate Democrats said Thursday it was investing $13 million in the state. But Iowa Democrats first need to settle on which federal candidate will be at the top of the ticket. Early voting began Wednesday.

Turek said his win in a Trump district will translate statewide, making him the best candidate to go up against a full-fledged Republican operation heading into the general election.

“My opponent, Zach Wahls, has never run against a Republican,” Turek said. “I know that there is something specific about my story, my background, my resume ... that really has this unique ability to win over independents, which are the kingmakers in the process, and moderate Republicans.”

Wahls said he's gone up against plenty of Republicans to advocate and “defend families like mine,” referencing a 2011 speech he made to Iowa lawmakers about his two moms that went viral. Wahls maintained that winning back rural and working-class voters lies with offering a different kind of Democratic Party and a new leader of Senate Democrats.

“We need to win back the trust of rural and blue-collar voters who were written off and lost by Chuck Schumer,” Wahls said. “We have a choice: Run the same playbook that Chuck Schumer ran and lose, or fight for the voters that he wrote off and win them back.”

Wahls has been critical of Turek for not rejecting Schumer as caucus leader. Turek says he would ask any leader candidate what they would do for Iowa and Iowans.

Both candidates focused their attacks Thursday on Hinson. Turek and Wahls, aligned on many issues, criticized votes Hinson has taken in the House to support Trump's agenda.

Each said he would not support the Republican president’s tariffs or the war in Iran. Wahls said Hinson had “rubber stamped” Trump's approach by voting againsta resolution Thursday to curb the president's powers in the Iran war, which Wahls blamed for higher gas prices and farmer input costs, including diesel and fertilizer.

Turek criticized Hinson's support for Trump’s tax and spending cuts package. He said he supports no tax on tips and overtime, which he described as policies that support the middle class, but said the law's cuts to Medicaid and food assistance exacerbated a “crisis in this state, unique to Iowa.”

Both candidates criticized corruption in Washington and proposed higher taxes on corporations and wealthy Americans.

Wahls criticized Turek for missing several votes on bills related to reproductive health care, including one that bans most abortions after about six weeks of pregnancy and another that would have criminalized the death of an “unborn person.”

Turek explained his absence during the one-day special session vote on Iowa's abortion law, saying he had a serious medical issue related to his disability. He apologized after “to all of my constituents for not being able to cast my vote against this bill on your behalf.”

Wahls also hit Turek for a vote he took in committee supporting a wide-ranging bill that included funding for centers that discourage women from getting abortions. Turek voted against the bill on the House floor.

Both candidates said they would work to codify access to abortion in the U.S. Senate.

While Wahls and Turek have raised and spent similar amounts, a Democratic political organization, VoteVets, has spent about $7 million to support Turek in the final stretch of the campaign. That's more than the two candidates have spent combined.

Turek, who is not a veteran, was born with spina bifida after his father’s exposure to chemicals while serving in the Vietnam War. The group has said Turek is uniquely positioned to advocate for veterans’ services, especially health care and military families.

Wahls has criticized the influx of cash as insiders in Washington trying to exert outsized influence.

Another group purchased more than $40,000 in airtime to support Wahls this week, according to filings. Iowa Action was funded by a lawyer with a California address who has also donated directly to Wahls' campaign.