Byron York of the Washington Examiner notes Democratic presidential nominee Hillary Clinton’s recent silence about the Affordable Care Act and her plans to tweak it or build upon its foundation.

The Affordable Care Act is Barack Obama’s signature achievement as president. It is the Democratic Party’s most important legislative accomplishment in two generations. It is something Hillary Clinton, although she left the Senate by the time ACA became law in 2010, worked for all her adult life.

So why doesn’t Clinton at least mention this great achievement as she campaigns for president?

A look at transcripts of Clinton stump speeches since she kicked off the general election campaign on Labor Day finds the Democratic candidate almost never talks about Obamacare. She doesn’t promise to expand it. She doesn’t promise to protect it. She doesn’t extol its benefits. She just doesn’t mention it.

There’s no doubt Obamacare is in trouble. Enrollment in the exchanges has fallen far short of projections. The purchasers of policies have turned out to be older, and in need of more care, than expected. Major insurers are pulling out of the exchanges altogether. Premiums are going up. Deductibles are skyrocketing, meaning many are left to pay most of their healthcare costs themselves.

Here’s one all-too-common headline, from Bloomberg on Friday: “Near ‘Collapse,’ Minnesota to Raise Obamacare Rates by Half.” The situation is being repeated around the country.

On her website, Clinton proposes to “defend and expand the Affordable Care Act.” She promises a public option, as well as a version of Medicare for all.

But she hasn’t been saying that on the stump in the general election campaign. Instead, when Clinton speaks of healthcare, she speaks of making it affordable, as if there were not already a massive, coercive and far-reaching law called the Affordable Care Act. It’s as if Obamacare never happened.