In less than 11 weeks, voters will go to the polling stations not just to choose the next president, but in many states to vote in Senate races. One week prior to that, Americans will enter their open-enrollment period for health insurance, including those forced into ObamaCare exchanges by the federal mandate. Those two events have a connection that might just tilt the Senate back to the GOP, thanks to skyrocketing premiums in swing states Democrats have to win to wrest back control of the upper chamber:

In nine of 11 states with competitive Senate races, at least one insurer seeks to hike rates for Obamacare customers by at least 30 percent next year: Highmark Blue Cross Blue Shield in Pennsylvania wants to jack up average premiums by more than 40 percent. In Wisconsin, three insurers have asked for rate hikes of more than 30 percent. In New Hampshire, two of the five carriers want to sell plans with rate increase above 30 percent.

The potential sticker shock — coupled with the likelihood many consumers will have fewer choices next year after major insurers scale back their exchange participation — creates a potential political opening for Republican candidates, especially since the next Obamacare enrollment season starts one week before Election Day.

“People who are feeling it in their pocketbooks are going to be very unhappy about [rate hikes],” said Brian Walsh, a former communications director for the National Republican Senatorial Committee. “You would expect to see this will be part of the campaign messaging for House and Senate Republicans. … If it hasn’t started, it will be coming.”

It could have been worse for Democrats. Like the previous years of ObamaCare, the open-enrollment start date has shifted from October 1 to November 1. The delay supposedly allows insurers to calculate more precisely the expected utilization rates and give states enough time to approve rate changes. Politically, however, it eliminates four weeks of building anger before Election Day, a clever trick that nevertheless failed to pay off at all in 2014.

This year, though, the escalations of premiums in insurer filings are so dramatic that the cost bomb will hardly be a secret on October 1. Consumers in these states have already begun feeling the impact of insurers withdrawing from the system, and have had to watch the markets carefully to see what premiums they will have to pay to replace their coverage. Thanks to those withdrawals, The Hill’s Peter Sullivan points out, states have almost no leverage at all to demand lower premiums from those insurers staying in the system:

State insurance officials say they are feeling pressure to approve large ObamaCare premium increases to prevent more insurers losing money from dropping out of the market altogether.

Tennessee’s insurance commissioner, Julie Mix McPeak, this week announced the approval of premium hikes of 62 percent, 46 percent and 44 percent, respectively, for the three insurers on the state’s marketplace.  …

McPeak, the Tennessee commissioner, said that part of her decision to approve the large premium hikes came from her fear that insurers could drop out if the increases were not approved, possibly leaving some consumers with no insurance option at all.

“We’re certainly not at a place of collapse right now, but I am very worried that, like I mentioned, any one carrier deciding to withdraw from our marketplace could cause a disastrous effect, because the other insurers may follow suit,” she said. “And at this point I don’t feel like we have a successful exchange because, like I said, half of our counties have only one option on the exchange today and so having any change in the level of competition may not allow our exchange to survive.”

Consumers who get subsidies “will not feel the full effects of these increases,” Sullivan notes, because of taxpayer subsidies. They will, however, certainly see the huge escalations in premiums and understand that the system is rapidly approaching a meltdown. Republicans who oppose ObamaCare — and have a plan to replace it — can use that to remind voters who shoved ObamaCare down their throats, and which party made promises about it that turned out to be entirely false.

Bet on that having more impact on swing-state Senate races than a presidential contest between two disliked candidates.