A nonpartisan group that’s planning to spend $1.75 million on TV ads supporting independent Angus King in Maine’s U.S. Senate race includes New York City Mayor Michael Bloomberg. The first of two ads sponsored by Americans Elect went into rotation on Friday. The Portland Press-Herald reports a group spokeswoman says Bloomberg, an independent, contributed $500,000. Americans Elect’s founder Peter Ackerman put in $500,000 and Passport Capital’s founder John Burbank contributed $750,000. King entered the race with a commanding lead, but the race has tightened. The former two-term governor and Republican Charlie Summers, secretary of state, are in a fierce contest to replace Sen. Olympia Snowe, a Republican. Also in the race are Democratic state Sen. Cynthia Dill and three other independents, Steve Woods, Andrew Ian Dodge and Danny Dalton.