More than two decades ago, when gay men and lesbians were prohibited from serving openly in the U.S. military and no state had legalized same-sex marriages, a national LGBTQ+ rights group decided to promote change by grading corporations on their workplace policies.

The Human Rights Campaign initially focused its report card, named the Corporate Equality Index, on ensuring that gay, lesbian, bisexual, transgender and queer employees did not face discrimination in hiring and on the job. Just 13 companies received a perfect score in 2002. By last year, 545 businesses did even though the requirements have expanded.

But the scorecard itself has come under attack in recent months by conservative activists who targeted businesses as part of a broader pushback against diversity initiatives. Ford, Harley- Davidson and Lowe’s are among the companies that announced they would no longer participate in the Corporate Equality Index.