A group of senators is demanding answers after a recent business move at Connecticut-based Aetna Insurance.

Former presidential candidate Bernie Sanders and Massachusetts Sen. Elizabeth Warren, among others, want the company to explain why it is dropping out of insurance exchanges in two-thirds of the areas it now covers.

They want to know if Aetna was motivated by the Justice Department's decision to challenge the company's proposed $37 billion merger with Humana.



In a letter made public last month, Aetna appeared to threaten to drop out of the public health care exchange if the Justice Department opposed the merger.