The midterm elections are less than a week from now, and polls show that large majorities of Americans want to keep the Affordable Care Act provisions that protect people with pre-existing conditions from being turned down because of their medical history (75 percent) or charged higher premiums (72 percent). It's no wonder then that politicians are trying to outdo each other in promising to never, ever take away such protections.

Yet many of the politicians now promising to protect pre-existing conditions have documented records of doing the opposite, voting for legislation or supporting lawsuits that would once again allow insurance companies to turn down such applicants, charge them higher premiums, and/or exclude coverage for the medical services they need.

So if you hear a politician who voted for the ACA repeal-and-replace bills last year, or who is involved in a current lawsuit to overturn the ACA's pre-existing condition protections, promise now to defend those protections, don't believe it. Here's why.

All the ACA repeal-and-replace bills considered by Congress last year would have allowed sale of insurance that doesn't cover the care that people with pre-existing conditions need. Requiring insurers to, say, cover cancer patients is meaningless if they are allowed to exclude coverage for chemotherapy.

None of the ACA repeal-and-replace bills had a viable alternative to ensure that premiums would be affordable, and that the plans would cover the care patients with pre-existing conditions need, so a vote for them was a vote to weaken protections for pre-existing conditions.

The bills also would have repealed Medicaid expansion and/or capped and cut the federal contribution to Medicaid. The result would have been millions more uninsured, many of them low-income people with pre-existing conditions.

Fortunately, none of those bills had enough votes to pass both the House and Senate, so the ACA's protections for pre-existing conditions remain (mostly) in effect. Even in the absence of repeal legislation, the Trump administration has acted on its own through the regulatory process to weaken them, proposing a rule that would allow sale of so-called "short-term" plans for up to a year (and then renewal for two more years) that are exempted from the ACA's requirements that essential benefits be covered. That would weaken pre-existing conditions in two ways. First, people who buy the short-term plans will find that they typically don't cover things such as prescription drugs, mental health and substance-use disorder treatments, or maternity care, so if they get sick or pregnant while enrolled in them, tough luck, the care they need likely won't be covered.  In Philadelphia, for instance, of the short-term plans that currently are on sale, just 33 percent of them cover prescription drugs or substance-use treatment, and only 57 percent of them cover mental health; none of them cover maternity care. Second, if a lot of healthy people buy these bare-bones plans, it will drive up premiums for people who have pre-existing conditions by removing healthy people from the insurance pool needed to keep premiums low for those who are sick.

And last week, the administration announced that it will allow states to get waivers to sell insurance that does not have to cover needed medical care.

There's also a pending lawsuit, brought by 20 Republican governors or state attorneys general, that asks a federal judge to rule that the ACA's pre-existing condition protections are unconstitutional. Many of those governors or attorneys general are now running for re-election or higher office this November.

Here's the bottom line: Members of Congress who voted for the ACA repeal bills are on record as voting to weaken or repeal protections for people with pre-existing conditions, without offering an alternative to ensure those patients would have access to affordable insurance that covers the care they need. The governors and state attorneys general who have brought the lawsuit to bring down the ACA are on record as wanting to overturn its pre-existing-condition protections, without offering an alternative to ensure patients will have access to affordable insurance that covers the care they need.

So why should anyone believe them now when they say they will protect patients with pre-existing conditions?