An early, shadowy poll in Maine’s 2018 gubernatorial race that looks aimed to ward off U.S. Sen. Susan Collins, who is considering running to replace Gov. Paul LePage, says she might have trouble surviving a Republican primary.

The conservative governor has escalated an intra-party war against the moderate senator since her key vote in late July against repealing the Affordable Care Act, which was the party’s No. 1 priority now that it has control over the executive branch and majorities in both chambers of Congress.

LePage began his attack on Collins at a private Republican event the weekend after the vote, saying she would “back down” from a run if his base rejected her. Last week, he called Collins and U.S. Sen. Angus King “dangerous” in a Wall Street Journal column.

It’s hard to say what the impact will be, and it’s worth noting that while Collins regularly wins approval ratings of 65 percent or higher in public polls, LePage has never cracked 50 percent.

But a poll from the Democratic firm Public Policy Polling that showed up in Politico on Tuesday seems to bear that out, even though it’s unclear who paid for the poll.

It showed former LePage Health and Human Services Commissioner Mary Mayhew — the only declared Republican candidate — leading Collins among 672 likely primary voters with 44 percent support to the senator’s 33 percent. But there are more results that cut both ways for Collins.

First, the very bad: More than six in 10 respondents said they disapproved of Collins and said her vote on Obamacare made it less likely they would vote for her, while 55 percent said they would be more likely to support a candidate who earned LePage’s endorsement.

The kernel of good news for Collins is that Mayhew doesn’t seem very strong, either. She has a 27 percent approval rating, but 23 percent disapprove and 50 percent didn’t know enough to form an opinion. A generic Republican also runs 18 points ahead of Mayhew when paired against Collins, according to the poll.

All of this bears out what several Republicans told the Bangor Daily News last week — that Collins would have big trouble in a primary. It also shows that LePage has the hearts of the base, tallying a 79 percent approval rating among Republicans, two points ahead of President Donald Trump.

But polls this early don’t reflect the environment that candidates will face next June in the primary election. It’s also a giant red flag that we don’t know who paid for the poll. Tom Jensen, the director for Public Policy Polling, said it was commissioned by an outside group but that his firm wasn’t authorized to release the poll or say who paid for it.

A spokesman for the Democratic Governors Association didn’t respond to a question about whether or not his group funded it. Groups like that would love to run against someone less widely popular than Collins.

In a statement, Collins spokeswoman Annie Clark said the senator “is not going to make a decision based on any poll.” Mayhew said in a statement that while she doesn’t put much stock in polls, “this may be a small indicator of the way our campaign is being received by the voters.”

This item was originally published in Daily Brief, a free political newsletter distributed Monday through Friday by the Bangor Daily News to inform dialogue about Maine politics and government. To read more of today’s Daily Brief, click here. To have the Daily Brief delivered daily to your inbox, click here.

Michael Shepherd joined the Bangor Daily News in 2015 after time at the Kennebec Journal. He lives in Augusta, graduated from the University of Maine in 2012 and has a master's degree from the University...