Massachusettes Attorney General Martha Coakley is arguing in new court filings that the federal law defining marriage as the union between a man and woman forces Massachusetts to discriminate against its residents and violates the traditional rights of states to regulate marriage.

Coakley has asked a U.S. District Court judge to rule, without a trial, that the federal Defense of Marriage Act is unconstitutional, the latest step in a lawsuit the attorney general filed in July challenging DOMA

The new court documents filed in U.S. District Court Thursday came in response to a motion from federal attorneys with the U.S. Justice Department to dismiss the case.

Coakley argues in the case that states have traditionally held the authority to regulate marriage, and that the Defense of Marriage Act violates the 10th Amendment of the U.S. Constitution, which prohibits Congress from interfering with laws that are the domain of states.

She also said the federal law forces Massachusetts to discriminate against same-sex couples who are married in Massachusetts when determining eligibility for Medicaid benefits or when a same-sex spouse requests burial in a veterans cemetery with their husband or wife.

Along with Coakley’s legal argument, the attorney general submitted 11 sworn affidavits from state officials and marriage experts testifying on behalf of the state.

In one statement, Dolores Mitchell, executive director of the Group Insurance Commission, testified that Massachusetts has had to spend $47,000 since 2004 to operate separate systems tracking the health benefits of opposite-sex spouses and same-sex spouses for tax purposes since same sex couple must pay tax  on that benefit because the federal government does not recognize the couple as married and Kevin McHugh, payroll director in the Office of the Comptroller, also testified that the state has had to pay an additional $122,607 in Medicaid payroll taxes because the federal government does not recognize same-sex marriages.

The Obama administration has already stated that it believes the Defense of Marriage Act is a discriminatory law that should be repealed, but the Department of Justice in the past has been upholding it.  If the DOJ does not  to respond to Coakley’s request for summary judgment by April 30th the U.S. District Court could rule DOMA as unconstitutional and thus make it null and void.

So it seems Martha Croakley’s loss to Scott (Cosmo) Brown for the MA Senate seat might actually in the long run be our gain.