Republicans once competed for the votes of women as a party that was officially committed to passing the Equal Rights Amendment and reasonably respectful of the right to choose. And the face of Republican feminism was Betty Ford.

The most politically outspoken first lady since Eleanor Roosevelt, and arguably the most candid first lady ever, Elizabeth Ann Bloomer Ford was during her time in the White House and the years immediately following the 1976 defeat of her husband Gerald Ford, a powerful and important advocate for women’s rights and one of the last nationally recognized and respected champions of socially liberal Republicanism.

Betty Ford’s death Friday, at age 93, came long after the Grand Old Party had formally and fully abandoned her values—and those of her mainstream Republican husband. In that sense, her death marks a broader passage politically than that of most former first ladies. It is difficult to imagine that the Republican Party will ever again send to the White House a woman who—as first lady or President (and there were more than a few commentators who suggested that Betty Ford would have made a fine commander-in-chief)—would unapologetically declare herself to be a feminist, support abortion rights,endorse pay equity and lead the fight for passage of the ERA.

But Betty Ford did all this, working closely with leaders of the National Organization for Women as a Republican “face” of the struggle to secure the rights of women.

“Betty Ford was the first first lady to really be consistently, publicly (outspoken) about women’s rights and women’s issues,” explained Susan Hartmann, a historian of feminism. “She was the most visible Republican feminist.”

When her husband assumed the presidency in 1974, after the collapse of Richard Nixon’s administration, he was the first president in American history to come to the position by appointment (Nixon has chosen him a year earlier to replace scandal-plagued Vice President Spiro Agnew) rather than elected as a member of a national party ticket.

That led some pundits to imagine that the Fords would be caretaker administrators.

But Betty Ford signaled immediately that she intended to be heard.

“I do not believe that being First Lady should prevent me from expressing my views,” she declared.

One of her top priorities was supporting the amendment of the Constitution to fully respect and protect the rights of women. The ERA was an old idea—"Equality of rights under the law shall not be denied or abridged by the United States or by any state on account of sex"—that had been proposed in slightly different form by women’s suffrage champion Alice Paul in 1923. Initially embraced by the Republican Party, which added a pro-ERA plank to the national platform in the 1940s, the amendment was eventually endorsed by the Democrats as well. After years of being introduced but not advanced in Congress, the ERA was finally approved by Congress in 1972 and sent to the states for ratification.

As first lady, Betty Ford called state legislators, urging them to vote for passage of the ERA. She even was photographed with a pro-ERA banner hanging from her desk in the White House.

Ford also spoke up for abortion rights, declaring in a CBS 60 Minutes interview: “I feel very strongly that it was the best thing in the world when the Supreme Court voted to legalize abortion and, in my words, to bring it out of the backwoods and put it in the hospitals where it belongs.”

These positions were controversial in a Republican Party that was shifting to the right. Gerald Ford was challenged for the 1976 GOP nomination by Ronald Reagan, and Reagan’s backers began the process of rewriting the party platform to remove planks supporting the ERA while including planks calling for overturning the High Court’s Roe v. Wade decision.

Betty Ford opposed both shifts by her party, and she took her hits from conservatives—as she did for her candid talk about sex and sexuality and marijuana use.

But the first lady’s refusal to veer to the right benefitted her husband’s uphill re-election campaign. Betty Ford’s poll numbers were better than those of Gerald Ford or the GOP—a reflection of the appeal of her frankness, not just on political issues but about her own struggles with breast cancer and substance abuse.

A popular pin 1976 campaign pin declared: “I’m for Betty’s Husband.”

Gerald Ford narrowly lost that year’s presidential race to Democrat Jimmy Carter.

But Betty Ford kept campaigning,

Appointed in 1977 by Carter to the second National Commission on the Observance of International Women’s Year, she participated in the National Women’s Conference in Houston, endorsing the convention’s National Plan of Action for improving the status of women in the United States.

As the battle over the ERA intensified in the late 1970s and early 1980s, Ford became even more active, constantly lobbying legislators in key states to back the amendment and traveling the country on its behalf. Ford co-chaired the National Organization for Women’s ERA Countdown Campaign in the early 1980s, working closely with NOW president Eleanor Smeal in a final attempt to win approval of the amendment in the handful of states that were needed to achieve ratification.

That effort failed, in large part because of opposition from the burgeoning “new right” movement that would come to dominate the Republican Party. While many other prominent Republicans who knew better—such as George Herbert Walker Bush—began to defer to what came to be known as the “religious right,” Betty Ford continued to advocate for what had until the 1970s been mainstream Republican positions.

Decades later, during the presidency of George W. Bush, Ford was still defending the Roe v. Wade decision and calling for a renewed campaign to ratify an Equal Rights Amendment.

It is perhaps a measure of the extent of the rightward drift—not in popular sentiment but in the approach of prominent players in both parties—that the feminism and social liberalism that Betty Ford espoused as a Republican first lady today seems even bolder and more politically adventurous than it did in the 1970s.

And it is surely a measure of the decay of ideological diversity in the Republican Party that her mainstream positions have no advocates among the contenders for the party’s 2012 presidential nomination or the many women who have moved to positions of prominence in the party thanks to the efforts of the suffragists and feminists who once saw the GOP as a vehicle for advancing the equal rights ideal that remains as vital necessary today as it was when Betty Ford spoke up.