When 20 of the Democratic presidential candidates take the debate stage Wednesday and Thursday, one key difference that could emerge is whether candidates say they would seek another overhaul of the nation’s health insurance system.

The debate will be an opportunity for the White House aspirants to outline their health care plans — an issue that polls consistently show is a priority for Democratic voters. Most of the party’s 24 candidates have yet to release their own comprehensive plans explaining their priorities on an issue that contrasts significantly with President Donald Trump’s approach.

While candidates have embraced different health plans to varying degrees of specificity, that may be by design, said Mark Mellman, president and CEO of the Mellman Group.

“Democrats have learned from very long experience going back to the ’90s that it is tricky, and when you get to the specifics, you can create problems for yourself,” he said.

Flashback: What if we switch to a single-payer health care system?

Nearly every candidate entered the race earlier this year to questions of whether they support “Medicare for All,” which is typically considered a single-payer health care system that would shift all Americans to a government-run insurance plan. At least 10 candidates have signed on to legislation that would implement a single-payer system or said they support that type of system, but several have also backed more incremental steps.

The setup of this week’s debates, with 10 candidates sharing the stage each night, may give candidates little time to offer up new details about their health plans.

A Kaiser Family Foundation poll released last week found health care to be the issue that most Democrats said was “very important” to discuss in the debates, with 87 percent agreeing. While 15 percent of those polled said they want to hear the candidates discuss a single-payer system, more than a quarter, or 28 percent, said they want to hear what a candidate would do to lower the cost of health care.

The issue of cost, which a key Senate panel that includes two presidential candidates will debate Wednesday, has so far earned less attention on the campaign trail than whether candidates are seeking to upend the current insurance system in favor of a single-payer plan.

Support for Medicare for All is important for candidates looking for support from progressives, but affordability issues, particularly for prescription drugs, are likely to be more important to a broader swath of primary voters, said Dan Mendelson, a former Clinton administration health official who founded the consulting firm Avalere Health.

“Based on polling data that I’ve seen, I think voters are much more motivated by the out-of-pocket costs than they are about Medicare for All,” said Mendelson, who has advised several of the primary candidates on health care policy.

Political risks

In fact, getting too in the weeds on single-payer could be detrimental to candidates, Mendelson said. Recent polls show Democrats are more open to a system in which anyone has the option to get Medicare or another government plan but isn’t required to shift into a single plan.

“When you start to define it, it starts to deteriorate as an issue,” he said. “People become uncomfortable with the idea that they would actually have to give up their present insurance and go into a government-run plan.”

That could benefit the candidates advocating a public option, which offers consumers a choice and would set up a government-run plan to compete with private plans in the individual market.

“The fundamental fact is everybody thinks the system needs pretty dramatic change, but they don’t want much change in their own health care coverage and it’s very hard to create a plan that changes the system without changing everybody’s relationships to that system,” Mellman said.

During the primary phase, candidates are seeking to draw comparisons between themselves and the others they’ll share the stage with. Still, some Democrats say it’s most important for candidates to showcase the differences between themselves and the Trump administration, particularly ahead of a July 9 hearing before the 5th U.S. Circuit Court of Appeals in which the administration will argue that the court should strike down the entire 2010 health care law.

“It’s an important question as to what Democrats want our health care system to look like 10 or 20 years from now,” Connecticut Democratic Sen. Christopher S. Murphy said. “The real present, clear danger is that if the lawsuit is successful, it could create a humanitarian crisis in this country that we would not be able to recover from.”

To some extent, all of the candidates will likely raise those issues while advocating their own positions, Mellman said.

“Everybody is going to be emphasizing the importance of expanding coverage and reducing cost and dealing with pre-existing conditions,” he said. “They’re going to have different ways of achieving those goals.”

Polling released this month by the left-leaning firm Navigator Research shows more support among the electorate for a plan that would make the Medicare program available to anyone but let people keep their current insurance plans if they prefer. That mirrors a proposal by Democratic Reps. Jan Schakowsky of Illinois and Rosa DeLauro of Connecticut, known as Medicare for America.

Former Texas Rep. Beto O’Rourke, who is running for the Democratic presidential nomination, supports that plan, which would offer a pathway to universal coverage but not require people to shift to a government-run plan.

That type of plan could let Democratic presidential candidates, for whom health care is a key issue, demonstrate to voters that they would seek to build from the 2010 health care law, but inoculate themselves against criticism that they support a government takeover of the system.

“They have to make clear that they’re for change, but their change is not as large as [a shift to single-payer] and that they really deeply care about the principle,” said Robert Blendon, a Harvard University professor who directs the Harvard Opinion Research Program.