Although their policy differences are stark, U.S. Rep. Ann Wagner and her Democratic rival, Cort VanOstran, frame their 2nd District contest in similar terms.

Said Republican Wagner, who is seeking her fourth term:

“Missouri 2nd Congressional District is personal to me. This is where I was born and raised. This is where I raised my family. It’s where I’ve worked. It’s where I volunteer. And it’s home.”

Said VanOstran, who’s making his first bid for public office:

“When I watched Ann Wagner vote with other Republicans in Congress to cut 23 million people like my mom off of their health care coverage, that felt very personal to me.”

The Wagner-VanOstran race is undisputedly Missouri’s most competitive U.S. House contest on the November ballot.

The 2nd takes in much of west and southern St. Louis County, along with portions of Jefferson and St. Charles counties. It produces more votes than any other House district in the state. So a heavy voter turnout could impact other races on the November ballot.

Although the district has leaned Republican for decades, some in both parties believe it has gotten more competitive for Democrats.

Wagner has more money in her campaign bank account, but VanOstran has outraised her for much of the past year.

Political veteran versus a newcomer

Both candidates are running a barrage of TV ads. And both recognize the stakes.

“It’s ‘go time’ folks!” declared Wagner at a recent canvass event in south St. Louis County. “We’ve got to go out, knock on those doors and turn out our votes.”

VanOstran, who is attracting sizable crowds, tells supporters that they face long odds. “We have no illusions,” he said. “This will be a David and Goliath race because of her support from lobbyists and special interests.”

Credit Jason Rosenbaum | St. Louis Public Radio U.S. Rep. Ann Wagner, center, mingles with Republican supporters in south St. Louis County on Oct. 13.

Wagner, 56, has been an influential political figure for decades. She’s the former chairwoman for the Missouri Republican Party, held prominent posts with the Republican National Committee and served as ambassador to Luxembourg during President George W. Bush’s tenure. She was first elected to Congress in 2012.

VanOstran, 30, grew up in Joplin. His father committed suicide when he was 8, leaving his mother to raise three children. With a scholarship from the local Elks Club, VanOstran attended Harvard University, then returned to Missouri for law school at Washington University. He stayed in the St. Louis area to practice law.

The national and state political parties are weighing in on the race. The Republican National Committee has set up four campaign offices in or near the 2nd District, while the state Democratic Party is running several coordinated-campaign offices to aid VanOstran and other Democratic candidates.

Health care is major focus

VanOstran’s key issue is why he opted to run for Congress: health care. His mother died of cancer two years ago.

He says she had access to good doctors and hospitals only because she could purchase affordable health insurance under the federal Affordable Care Act.

VanOstran says he decided to challenge Wagner because she has consistently voted to repeal the ACA, and backed GOP alternatives that would strip protections for people who have pre-existing health conditions.

“What we’ve seen from the Republicans in Congress is not a desire to improve the ACA,’’ VanOstran said. “They’ve taken every opportunity to gut the protections it does provide.”

He points to the federal tax cut bill approved late last year, which eliminated the ACA’s mandate that all Americans pay for health insurance. The result is weakening the ACA’s other provisions, and making it more difficult to keep insurance prices down, VanOstran said.

Wagner says she also supports protecting people with pre-existing conditions. But she believes a different approach is needed.

“Our current system through the ACA is unaffordable, it’s unworkable. We need something that’s patient-centered,” she said.

Wagner cites previous GOP efforts to allow health insurance to be purchased across state lines, and beef up health care savings accounts.

“We need to put this back in the free market and take it out of the government’s hands,’’ she added.

Variety of backers

Both candidates are relying on armies of volunteers. Dozens of VanOstran backers packed a Kirkwood campaign office on a recent Saturday, and several hundred showed up at a weeknight event in a west county library.

Becky Morgan with Moms Demand Action was among them.

Credit Jo Mannies/St. Louis Public Radio Democratic congressional candidate Cort VanOstran addresses potential supporters at a campaign event in west St. Louis County.

“He’s with us on this issue of common-sense gun safety policies that will reduce gun violence and save lives,” Morgan said.

Wagner’s backers include a number of law enforcement groups, including the International Association of Fire Fighters and the St. Louis County Police Association.

“Ann is a true champion for first responders,’’ said Kurt Becker, district vice president for Fire Fighters Local 2665. He praised her work on various issues, including helping to set up a national firefighters cancer registry act.

Wagner cites her efforts to aid the nation’s financial industry. But she agrees she’s best known for her work against sex trafficking, which resulted in this year’s passage of the Fight Online Sex Trafficking Act, which outlawed such online sex-advertising sites as BackPage.com.

“Congress never intended for the internet to be a ‘red light district,’” Wagner said. “So, that is a major accomplishment we’ve gotten done that I believe will save lives.”

Sparring over entitlements

Wagner emphasized that she opposes expanding Medicare to cover all Americans, which some Democrats support.

“Not only is it a bad idea to have the federal government in charge of our health care again, we’re trying to unwind that system that has brought us down and raised costs so high over the last eight to 10 years,” she said.

VanOstran says that the federal Medicare program is well run, and contended that the Democratic proposal to allow people under age 65 to buy-in reflects a quest to offer the best option for people who cannot get health insurance otherwise.

“I think there are other fixes that are more politically attainable in the short term,” he said. “I think ‘Medicare for All’ is a good goal for the long term.”

VanOstran also asserted that Wagner’s vote for the federal tax-cut bill is endangering the future of Medicare and Social Security, as well. Democrats point to Senate Majority Leader Mitch McConnell’s recent statements that the programs will need to be scaled back to curb the nation’s budget deficits.

Wagner said, “it’s a lie’’ to infer that she would support any cuts in Medicare or Social Security.

VanOstran and his allies also attack Wagner for failing to hold public town halls and not agreeing to debate. Wagner contends that the bulk of his campaign contributions are coming from “coastal elites’’ with few ties to Missouri.

Such attacks are expected to heighten as their contest heads into the final weeks.

Follow Jo Mannies on Twitter:@jmannies