The sudden uncertainty surrounding the future of the Affordable Care Act could be an enormous political liability for Republicans in key states come November.

Between the lines: Millions of people in crucial presidential and Senate battlegrounds would lose their health care coverage if the Supreme Court strikes down the law, as the Trump administration is urging it to.

The chart above shows the number of people enrolled in the ACA's insurance marketplaces or covered through its Medicaid expansion.

• These options have become especially important over the last six months, as millions of Americans lost their jobs — and thus their employer insurance — due to the pandemic.
• And more than a quarter of non-elderly Americans have a pre-existing condition that insurers in the individual market could refuse to cover without the ACA, per the Kaiser Family Foundation.

The big picture: Republicans paid a steep electoral price for trying to repeal parts of the ACA in 2017. Republicans' lawsuit against the health care law, if it succeeds, would boot even more people off of their coverage and undo even more of the ACA's regulations.

What to watch: Several vulnerable Republicans, including Sens. Susan Collins, Martha McSally, and Cory Gardner, represent purple states that expanded Medicaid and would therefore see steep coverage losses. And the broader fight over the Supreme Court has made it impossible to ignore those stakes.

• "With the Court setting Nov. 10 as the date for hearing California v. Texas, Republicans caught a break not having it front and center right before the election.  Now it is very much front and center," said Rodney Whitlock, a former health aide for Sen. Chuck Grassley.
• "Debates over protection of pre-existing conditions have generally not gone positively for Republicans in purple states/district," he added.

The coronavirus is surging once again across the U.S., with cases rising in 22 states over the past week, Axios' Sam Baker and Andrew Witherspoon report.

The big picture: There isn't one big event or sudden occurrence that explains this increase. We simply have never done a very good job containing the virus, despite losing 200,000 lives in just the past six months, and this is what that persistent failure looks like.

By the numbers: The U.S. is now averaging roughly 43,000 new cases per day, a 16% increase from a week ago.

• The biggest increases are largely concentrated in the West and Midwest, though Maine and New Jersey also saw their new infections tick up over the past week.
• Seven states — Arizona, Colorado, Minnesota, Montana, Texas, Utah and Wyoming — saw their daily infections rise by at least 60% over the past week.

Testing was up by almost 22% over the same period. The U.S. is now conducting about 860,000 coronavirus tests per day.

What's next: There's every reason to believe the next several months will be a particularly high-risk period.

• Colder weather will cause people to move indoors, where the virus spreads more easily.
• The best way to manage that risk is to enter into it with a low number of cases.
• The NIH's Anthony Fauci has said cases should ideally be below 10,000 per day heading into the fall. But we haven't been able to consistently keep them under 40,000.

Some of the same technological advances that have enabled us to partially weather the economic and health tolls of the pandemic may be paradoxically discouraging us from taking fuller measures, Axios' Bryan Walsh reports.

Why it matters: Thanks to tech like video chat and automation, a large portion of the population has been able to mostly escape the effects of the pandemic — and even thrive in some cases. But far too many of us risk being left further behind as the virus spreads.

The reality is that both the human and economic costs could have been so much worse. Imagine, for instance, if the SARS outbreak in 2003 had gone global with the same rough profile as COVID-19.

• A COVID-19 pandemic in 2003 would have presented the world and the U.S. with an impossible choice: pursue social distancing and experience even far greater economic havoc than we're seeing now, or try to weather the virus and watch the death toll climb.

Bryan's thought bubble: As much as the technology of 2020 has helped blunt some of the worst effects of the COVID-19 pandemic, it has also paradoxically held us back from making the hard choices that would be needed to fully beat the coronavirus in a more just way.

The bottom line: The uniquely dysfunctional government and politics of 2020 bear a major responsibility for how the pandemic has unfolded in the U.S. But we've also followed the lead of our tools to do what seems easy, as opposed to what is necessary.

Go deeper.

The debate over how the coronavirus is spread — via aerosols or droplets — isn't just theoretical. It matters in particular for how frontline workers protect themselves, Kaiser Health News reports.

Driving the news: These health care workers are fighting with infection control specialists and hospital administrators about the method of spread, and thus what kind of protective gear they need, per KHN.

• The argument resembles one being had at much higher levels. The Centers for Disease Control and Prevention recently came under fire for acknowledging spread via aerosols on its website, and then abruptly removing the guidance.

Between the lines: "The topic has been deeply divisive within hospitals, largely because the question of whether an illness spreads by droplets or aerosols drives two different sets of protective practices, touching on everything from airflow within hospital wards to patient isolation to choices of protective gear," KHN reports.

• "Enhanced protections would be expensive and disruptive to a number of industries, but particularly to hospitals, which have fought to keep lower-level 'droplet' protections in place."

What they're saying: "The best approach to communication I've found is that this requires enhanced respiratory protection in a healthcare setting," Arizona epidemiologist Saskia Popescu tweeted earlier this week.

• "It's not entirely airborne and it's not entirely droplet, but rather something in the middle."

Johnson & Johnson has begun phase 3 trials in the U.S. for its one-shot coronavirus vaccine, with plans to enroll the most participants of any trial yet.

Americans' political affiliations could determine which source they trust for information about the coronavirus, with 51% of Republicans saying they trust President Trump over CDC scientists, according to a Quinnipiac poll out Tuesday.

Missouri Gov. Mike Parson (R) and First Lady Teresa Parson tested positive for coronavirus, the governor's office announced Wednesday.

CDC director Robert Redfield said at a Senate hearing Wednesday that preliminary data shows that over 90% of Americans remain susceptible to COVID-19 — meaning they have not yet been exposed to the coronavirus.

Food and Drug Administration commissioner Stephen Hahn promised that "science will guide our decision" for a coronavirus vaccine at a Senate hearing on Wednesday.