South Dakota independent Senate candidate Larry Pressler is surging, and Republican Mike RoundsMarion (Mike) Michael RoundsOvernight Tech: Regulators to look at trading in bitcoin futures | Computer chip flaws present new security problem | Zuckerberg vows to improve Facebook in 2018 Senate sex trafficking bill wins 60 co-sponsors Five key decisions for the GOP on health care MORE has just a single-digit lead over the field in a new survey conducted for Democrat Rick Weiland’s campaign.

The internal automated poll, conducted by Democratic firm Public Policy Polling, gives Rounds 35 percent support to 28 percent support for Weiland and 24 percent support for Pressler, while 8 percent support independent Gordon Howie.

That’s a decline in support for both Rounds, a former governor of the state, and Weiland since the Democrat’s last internal poll, conducted at the end of August. Then, Rounds took 39 percent support to Weiland’s 33 percent support, and Pressler drew 17 percent.

The polling memo written for Weiland’s campaign suggests the race could be a late-breaking opportunity for national Democrats, who largely wrote off South Dakota when they failed to recruit a strong challenger into the race. And Rounds does indeed look to be more vulnerable to defeat than initially expected in the deep-red state. He’s faced attacks over his role in the scandal surrounding an investments-for-visas program in the state.

He’s underwater in the new poll, seen unfavorably by 51 percent of those surveyed.

But rather than an opportunity for Weiland, the new numbers seem to suggest Pressler, a former GOP senator, may have the best shot at defeating Rounds this fall. A Nielson Brothers poll out in late September suggested as much, showing Pressler slightly more competitive against Rounds than Weiland, if one or the other dropped out of the race and set up a three-way contest.

Neither candidate has given any indication he is willing to do so, however.

The poll was conducted among 703 likely voters Sept. 29–30 and has a margin of error of 3.7 percentage points.