Former Maine Gov. Angus King (I) topped a Pine Tree State Senate horserace matchup in a new poll released today.

In a survey of likely voters, King received 50 percent, GOP nominee Charlie Summers got 23 percent and Democratic nominee Cynthia Dill picked up just 9 percent. Seventeen percent of those polled didn’t know or were undecided.

King, elected to his first of two consecutive terms as governor in 1994, is highly regarded. A whopping 60 percent had a favorable impression of him while 21 percent had an unfavorable impression of him. Thirteen percent of those polled were undecided, and only 5 percent said they had never heard of him.

King has not said which party he would caucus with, if elected. Top officials in Washington, D.C., however, believe he would caucus with the Democrats.

“He is kind of the de facto Democratic candidate,” Senate Minority Leader Mitch McConnell (R-Ky.) told Roll Call last month. “It looks to me like [Democrats have] adopted him.”

Also, half of those polled had a favorable impression of President Barack Obama; 39 percent viewed the president unfavorably. The poll, done by the MassINC Polling Group for WBUR, surveyed 506 likely Maine voters June 13-14. MassINC used live telephone interviewers to survey respondents on land lines and cellphones. The poll had a margin of error of 4.4 points.

Read the full topline results here:

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