Portland pollster Market Decisions this morning released the results of a sample of likely voters from its "Maine Survey," with the latest statistics from the presidential and Senate races, as well as the state's referendum questions.

The survey found that Democratic presidential nominee Barack Obama leads Republican nominee John McCain, with 52 percent intending to vote or leaning toward voting for Obama and 33 percent intending to vote or leaning towards voting for McCain. The survey found 6 percent undecided.

Sixty-Five percent of Obama voters said the economy was their top concern.

"What a difference a year makes," said Curtis Mildner, president of Market Decisions, in a statement. "Last fall the presidential election was expected to be a referendum on the war in Iraq. Now it's all about the economy."

In the race for Senate, Republican Sen. Susan Collins leads Democratic U.S. Rep. Tom Allen, with 54 percent intending to vote or leaning towards voting for Collins and 37 percent intending to vote or leaning towards voting for Allen. Eight percent are undecided.

A yes vote on Question 1, which would repeal a new beverage tax put into place to help fund the Dirigo health program, is leading, Market Decisions found, with 66 percent intending to vote or leaning toward voting that way and 28 percent intending to vote or leaning toward voting No. Six percent are undecided.

A referendum question that would legalize a casino in Oxford County is "too close to call," Market Decisions found. According to the survey, 49 percent plan to vote or are leaning toward approval, while 48 percent are in the "no" category. Four percent are undecided.

"The casino vote could come down to the wire," said Brian Robertson, research director at Market Decisions.

The survey is a sample of 387 likely Maine voters, and has a margin of error of 5 percent.