What happened in Missouri yesterday is quite remarkable. By nearly a 3-to-1 margin, voters rejected a key provision of President Obama’s health-care law. More than 70 percent of Missouri voters backed a ballot measure, Proposition C, that would prohibit the government from requiring people to have health insurance or from penalizing them for not having it.

“It is likely to give Republicans a chance to brag about the unpopularity of ObamaCare,” Karen Ball of Time reports, “but the vote will be largely symbolic.” (Courts will decide whether Missouri and other states can legally trump federal law and exempt citizens from the mandate to buy insurance.)

Symbolic is one way to describe Tuesday’s vote; ominous (for the Democrats) is another.

This is yet one more electoral manifestation of the dismal polling numbers the Democrats have been facing for many months now. We saw rising popular opposition to ObamaCare throughout last summer, which many liberals ignored or ridiculed. Then came the gubernatorial elections in Virginia and New Jersey and the Senate election Massachusetts. Since then the opposition to ObamaCare specifically, and to Obama more generally, has increased; as a result we saw the 40-plus point trouncing in Missouri, a margin far higher than most people anticipated.

It is hard to overstate the toxicity of the Obama agenda. Losing a net total of 65 or more Democratic House seats is now possible (if not yet likely). We are less than 100 days away from what looks to be an inflection point, one of those rare mid-term elections that alter the trajectory of American politics.