WATCH: NOM's Finances Are Even Worse Than We Thought

The National Organization for Marriage is barely clinging to life, according to the group's reluctantly released tax returns for 2013.

The Human Rights Campaign had to ask repeatedly for the returns, which NOM only provided several days after the legally required deadline.

The main findings: NOM's donors have vanished, with 2013 fundraising barely half what it was in 2012. Meanwhile, NOM's debt has ballooned to from $2 million in 2012 to $2.5 million in 2013. Of the $5.1 million that NOM raised last year, more than half came from just two donors. That's down from three major donors in 2012.

The group's decline is likely attributable to multiple factors, such as its various fines for campaign finance violations and expensive but fruitless litigation to roll back marriage equality and paint itself the victim of a radical "gay agenda." The organization has also suffered a string of high-profile failures, barely managing to chalk up even the slimmest of victories in recent years. NOM's last major win was the passage of an antigay constitutional amendment in North Carolina in 2012, which has since been overturned.

Tthe organization spent $200,000 to support two antigay U.S. Senate candidates in the November election, Thom Tillis and Tom Cotton. And while both candidates won, NOM is unlikely to get much of a return on its investment. In Tillis's home state of North Carolina, marriage equality is firmly the law of the land, and Cotton is unlikely to be able to influence the state and federal lawsuits in his home state of Arkansas.

Get up to speed on the state of marriage equality amid NOM's funding crisis below: