In the 2014 midterms, Republicans ran a slew of attack ads on President Barack Obama and his signature health-care law. Democrats countered by doubling down on local issues and avoiding the referendum on Obama's policies.
Four years later, party advertising agendas have flipped.
This cycle, Democrats have put health care front and center, one year after failed GOP efforts to repeal and replace the Affordable Care Act. A recent analysis from the Wesleyan Media Project showed that health care was the most common subject of televised advertisements by Democrats for both the House and the Senate.
On the other hand, GOP candidates are nationalizing election bids by touting closeness with President Donald Trump while bashing Democratic leaders like Nancy Pelosi. Trump garners more praise in Republican ads this cycle than any other president in the past 16 years, while Obamacare figures in only 1 percent of Republican ads, according to the Wesleyan count.
"Clearly, Republicans are 'all in' when it comes to Trump in 2018, hoping that embracing the president will entice Republican voters to the polls," says Erika Franklin Fowler, co-director of the Wesleyan Media Project. "Democrats, by contrast, are not using Trump as a foil to the extent that Republicans used Obama in the past."
Here are what some of the latest ads from Republicans and Democrats are saying, and what they're leaving out.
Trump acolytes disparage 'gang of liberals'
The candidate: Former U.S. Rep. Ron DeSantis is running against progressive Democrat Andrew Gillum in Florida's closely watched governor's race.
The ad: DeSantis uses his family to pay homage to Trump and his policies, with his wife Casey, a Florida TV personality, narrating the message. "Ron loves playing with the kids," she says, as the ad cuts to DeSantis teaching his child to "build the wall" with blocks. He also reads Trump's book "The Art of the Deal" to their infant, and later coos "big league" to the baby, who wears a Make America Great Again onesie.
DeSantis has based nearly his entire campaign around his allegiance to Trump, who endorsed DeSantis and dismissed his opponent as a "failed Socialist."
The candidate: Brian Kemp, Georgia's secretary of state and self-described "politically incorrect conservative," is running against Stacey Abrams in a governor's race that will test whether the transforming Southern state prefers a Trump-endorsed conservative or a progressive black woman.
The ad: "I'm Brian Kemp, and I believe in God, family and country – in that order," he says. "I say Merry Christmas, and God bless you. I strongly support President Trump, our troops and ironclad borders. I stand for our national anthem. If any of this offends you, then I'm not your guy."
Kemp's ads all run with similar imagery: his guns, his truck — which he'll use to "round up criminal illegals and take 'em home myself" — and his chainsaw, which is "ready to rip up some regulation."
The candidate: After his narrow win in a heated Ohio special election, state Sen. Troy Balderson faces Danny O'Connor once again in the 12th Congressional District.
The ad: "Nancy Pelosi and her gang of liberals won't like me," Balderson sternly remarks after touting his plan to end sanctuary cities, build "the darn wall" and fully implement the president's agenda.
Adherence to Trump is apparently paying off for the candidate. A recent CBS News 2018 Battleground Tracker poll rates Ohio's 12th District "lean Republican" as does Sabato's Crystal Ball.
The candidate: Senate candidate Matt Rosendale is running against Democratic incumbent Jon Tester in Montana. Both candidates are sparring over who has a more authentic connection to the state, which Trump won by 21 points.
The ad: "Montana needs a conservative who's willing to back the Trump agenda, and not kowtow to Nancy Pelosi," Rosendale says. He criticizes Sen. Tester on taxes.
Tester voted against the GOP tax overhaul bill and called it "one of the sh---iest bills that's ever come in front of the Senate." The Senate voted 51-48 to pass the bill.
The candidate: Republican Gov. Rick Scott is hoping to unseat Democratic Sen. Bill Nelson in Florida. They are currently tied in the polls.
The ad: Scott frequently attacks his opponent for toeing the Democratic Party line, accusing Nelson of voting with his own party 89 percent of the time. "Bill Nelson's chair is empty even when he's in it," the narrator says, pointing out that Nelson failed to attend 45 percent of meetings on national security.
The Trump-endorsed Republican accuses Nelson of plans to oppose Trump's Supreme Court nominee Brett Kavanaugh.
Democrats attack GOP on health care
The candidate: Sen. Joe Manchin is running a tough re-election bid in West Virginia, where approval of Trump is near the nation's highest.
The ad: Imitating a 2010 ad in which he shot a hole in a cap-and-trade climate bill, the senator in a new ad takes his rifle and shoots a hole in a lawsuit that could eliminate protections for pre-existing conditions. His opponent, Patrick Morrisey, is a party to the lawsuit. "He's just dead wrong, and that ain't gonna happen," Manchin says of Morrisey.
Manchin, who has avoided citing the health-care law by name, wants to protect a core provision under the Affordable Care Act in a state where 29 percent of the population is on Medicaid.
The candidate: Antonio Delgado, a lawyer, is running against incumbent Republican Rep. John Faso in New York's 19th District, which is slated to be one of the most competitive in November.
The ad: Andrea Mitchell, a constituent with pre-existing conditions, tells the story of how Delgado's opponent, Faso, promised to protect her health coverage. But 100 days later, Faso voted to repeal the Affordable Care Act, a vote toward ending protections for her illness, she says.
Delgado, who is running in a toss-up district Trump won in 2016, has called for a more aggressive federal role in health care. His opponent says that he plans to keep portions of the health-care bill that cover pre-existing conditions.
The candidate: Elissa Slotkin is a former intelligence analyst who worked for the CIA and the Defense Department. She is running to unseat Republican incumbent Mike Bishop in Michigan's 8th District.
The ad: Slotkin describes her mother, who survived breast cancer, lost her job and health insurance, and developed stage 4 cancer. "It could be about anyone's mom," she says, criticizing her opponent for voting to dismantle parts of the Affordable Care Act.
Slotkin is one of several Democratic candidates who use family or personal experiences with illness and insurance coverage to promote their commitment to health care.
The candidate: Sen. Claire McCaskill of Missouri is running a tight race for re-election against Josh Hawley, the state's attorney general. Trump won Missouri by more than 18 points.
The ad: "Two years ago I beat breast cancer," McCaskill says. "Like thousands of other women in Missouri, I don't talk about it much." She criticizes her opponent for filing a lawsuit that would allow insurance companies to deny coverage for people with pre-existing conditions.
Like other Democrats in red states, McCaskill does not mention Obamacare broadly, but focuses on the pre-existing conditions provision.
The candidate: Sen. Heidi Heitkamp is running for re-election in a competitive North Dakota race against Kevin Cramer, the state's three-term congressman.
The ad: Heitkamp and one of her constituents, Denise Sanvick, both have pre-existing conditions. "For me, it's breast cancer. For Denise, it's heart disease," Hietkamp says. Sandvick then speaks to the camera to condemn Cramer's vote for the Republican health bill in 2017. "I know Heidi would never do that," she says.
Like Manchin and McCaskill, Hietkamp does not mention the law by name, but focuses on protections for pre-existing conditions.