Orono state Sen. Emily Cain has a $300,000 war chest less than five months away from her 2nd Congressional District primary against fellow Democrat Troy Jackson, the Maine Senate majority leader from Allagash.

Cain’s campaign released new fundraising numbers Wednesday, and also gave the Kennebec Journal and Morning Sentinel a summary of a mid-January internal poll showing her leading Jackson by 15 points among Democratic primary voters in the district.

However, about half of the 400 people surveyed by the Cain campaign said they were undecided ahead of the June 2014 primary, which Jackson’s campaign said showed an electorate that is up for grabs.

“It’s just a long time before Election Day,” said Alan Brewer, Jackson’s spokesman. “I think it’s a very open race.”

Cain and Jackson, along with political newcomer Alden Smith, a former Navy officer from Sangerville, are running for the Democratic nomination for the seat to be vacated by U.S. Rep. Mike Michaud, a Democrat who is running for governor.

On the Republican side, Kevin Raye of Perry, a former Maine Senate president who lost to Michaud in 2002 and 2012, is squaring off against Bruce Poliquin, the former state treasurer from Oakland.

Conservative Blaine Richardson, a former Republican from Belfast, is running as an independent.

Cain’s campaign said she more than doubled her past fundraising haul in the fourth quarter of 2013, raising $157,900. In a Wednesday announcement, the campaign said more than half her money has come from Maine.

“The support that we’ve seen throughout the district is incredibly important and it’s a very strong showing at this point in the game,” said Dan Cashman, Cain’s campaign spokesman.

Fundraising figures aren’t due to the Federal Election Commission until Jan. 31, which is when Jackson will release his, Brewer said.

Jackson filed for the race two weeks after Cain, and he was behind in fundraising as of September’s end, when Cain had roughly $143,000 to his $72,000. Both can tout contributions from top Democratic donors.

Cain has gotten maximum $2,600 contributions from Adam Lee, chairman of Lee Auto Malls, and S. Donald Sussman, majority share owner of MaineToday Media, owner of Kennebec Journal, Morning Sentinel and Portland Press Herald. Sussman is married to U.S. Rep. Chellie Pingree, D-1st District.

Jackson got a $1,000 contribution from high-powered Hallowell lobbyist Severin Beliveau and a maximum contribution from state Sen. James Boyle, D-Gorham.

Brewer didn’t give specific amounts for what to expect of Jackson’s money total, but said he’s not in a money race with Cain.

“I don’t think we ever anticipated matching dollar-for-dollar, but we’re hitting all the milestones we set for our campaign,” Brewer said. “We’re on target.”

Cain’s poll was the first one publicized in the Democratic primary, and Brewer said Jackson’s campaign hasn’t commissioned one yet.

The poll summary showed Cain with 32 percent to Jackson’s 17 percent among likely primary voters, leading among all age groups and by 24 points among women.

Brewer wouldn’t comment on the results, but said the summary “doesn’t give you much to go on.”

mshepherd@centralmaine.com

Twitter: @mikeshepherdme