Arkansas and Kentucky lead all other states in the sharpest reductions in their uninsured rate among adult residents since the healthcare law’s requirement to have insurance took effect at the beginning of the year. Delaware, Washington, and Colorado round out the top five. All 10 states that report the largest declines in uninsured rates expanded Medicaid and established a state-based marketplace exchange or state-federal partnership.

In Arkansas, the rate of uninsured dropped from 22.5 percent in 2013 to 12.4 percent now — a change of over 10 percentage points.

In Kentucky, it dropped from 20.4 percent to 11.9 percent — a change of over eight percentage points.

In Colorado, it dropped from 17 percent to 11 percent — a change of six percentage points.

The Kentucky example is particularly interesting. Remember, Mitch McConnell still regards the the law that created this drop in the uninsured among his own constituents as a “disaster.” Yet hundreds of thousands have signed up for coverage on the Kentucky exchange. Interestingly, as Joe Sonka has documented, the biggest drops in uninsured have occurred in eastern Kentucky — which is to say anti-Obama coal country, a.k.a., Mitch McConnell country.

Despite all this, Alison Lundergan Grimes continues to avoid engagement on Obamacare. I get the arguments in favor of that strategy. Grimes wants to avoid getting drawn into Washington arguments that could sully what the campaign sees as her key advantage in this race: The contrast between Grimes’ newcomer status and McConnell’s decades inside the Beltway. But it really is too bad that the Affordable Care Act — or, at least the word “Obamacare,” anyway — remains so toxic on some turf that Dems can’t embrace this steep drop in uninsured, in one of the most unhealthy regions in the country, as a major policy success.

The Arkansas example is also interesting. Arkansas moved forward with its own version of the Medicaid expansion, which presumably helped bring that rate down, and it’s noteworthy that the GOP candidate for Senate — Rep. Tom Cotton — has tended to serve up word salad when asked where he stands on it.

Meanwhile, the Koch-founded Americans for Prosperity has spent big money on multiple ads in Arkansas featuring Obamacare “horror stories” in which the victim in each…received a cancellation letter. Yet according to Gallup, the drop in uninsured here has been steeper than in any other state — which complicates the message that the law has ended up costing more people their insurance than it has covered.

All of these little data points help tell a larger story, which Politico told really well today: The fading of Obamacare as an issue in many states, including those with hard fought Senate races with massive expenditures such as those from the Koch group. To be sure, Dems very well could lose control of the Senate. But it is becoming increasingly accepted that even if that does happen, Obamacare might not be a major reason why — the makeup of the map and the economy could prove far more important in determining the outcome. Note this key nugget at the end of the Politico story:

Public opinion about the ACA does appear to have taken a dip in recent weeks, with the Kaiser poll showing 53 percent holding an unfavorable view in July. But there is little evidence that political messaging is having much effect. At the request of POLITICO, Kaiser polling experts compared 10 Senate battleground states subject to heavy advertising to 10 comparable states without competitive statewide races.
Over three months, May through July, 34 percent expressed favorable views of the law in the battleground states, compared with 35 percent in the other group. Unfavorable views were held by 51 percent in states with highly contested races, compared with 49 percent in the others. None of those differences are statistically significant.

Really, nobody could have predicted any of this would happen.