Independent expenditure groups spend money to influence the outcome of a city election, without the involvement of any candidate but may refer to candidates running for city offices. (politico.com)
Also note the possibility of a big Dem independent expenditure group forming. (epolitics.com)
Common Cause released a report last month showing the rise of independent expenditure groups in the 2013 elections, primarily in New York City. (nystateofpolitics.com)