Sen. Lisa Murkowski (R-Alaska) expressed support for gay marriage Wednesday, becoming the third sitting Republican senator to do so.

The Human Rights Campaign, a pro-gay rights group, announced the Alaska senator had backed marriage equality in a statement.

"This is a hard issue. It is hard because marriage is such a deeply personal issue," Murkowski told Anchorage television station KTUU. "There may be some that when they hear the position that I hold that are deeply disappointed. There may be some that embrace the decision that I have made."

"I recognize that it is an area that as a Republican I will be criticized for," she added.

Murkowski had said in March that her views were shifting on the issue. "The term 'evolving view' has been perhaps overused, but I think it is an appropriate term for me to use," she said.

Her endorsement comes as the Supreme Court is expected to rule in the coming days on the constitutionality of the Defense of Marriage Act and California's gay marriage ban, Proposition 8.

“Senator Murkowski’s courageous and principled announcement today sends a clear message that marriage equality must come to all 50 states in this country," said HRC President Chad Griffin. "As the Supreme Court prepares to rule in two landmark marriage cases this month, a growing bipartisan coalition is standing up for the right of all couples to marry—and there is no turning back that tide."

Murkowski joins Republican Sens. Rob Portman (Ohio) and Mark Kirk (Ill.) in supporting same-sex marriage. Fifty-one Senate Democrats favor it as well.

UPDATE: 10:50 a.m. -- In a statement on marriage equality, Murkowski spoke of an Alaskan lesbian couple who adopted four children and said the family's story influenced her thinking:

Yet despite signing up and volunteering to give themselves fully to these four adorable children, our government does not meet this family halfway and allow them to be legally recognized as spouses. After their years of sleepless nights, after-school pickups and birthday cakes, if one of them gets sick or injured and needs critical care, the other would not be allowed to visit them in the emergency room – and the children could possibly be taken away from the healthy partner. They do not get considered for household health care benefit coverage like spouses nationwide. This first-class Alaskan family still lives a second-class existence.

She also explained how her views have changed since backing a state gay marriage ban in 1998:

With the notion of marriage – an exclusive, emotional, binding ‘til death do you part’ tie – becoming more and more an exception to the rule given a rise in cohabitation and high rates of divorce, why should the federal government be telling adults who love one another that they cannot get married, simply because they happen to be gay? I believe when there are so many forces pulling our society apart, we need more commitment to marriage, not less.

This thinking is consistent with what I hear from more and more Alaskans especially our younger generations. Like the majority of Alaskans, I supported a constitutional amendment in 1998 defining marriage as only between a man and a woman, but my thinking has evolved as America has witnessed a clear cultural shift. Fifteen years after that vote, I find that when one looks closer at the issue, you quickly realize that same sex unions or civil marriages are consistent with the independent mindset of our state – and they deserve a hands-off approach from our federal policies.

Read her full statement here.

Also on HuffPost:

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  • Connecticut

    Since November 12, 2008

  • Delaware

    Gay marriage law <a href="http://www.huffingtonpost.com/2013/05/07/delaware-gay-marriage-law-_n_3232771.html" target="_blank">enacted</a>, weddings to begin July 1.

  • Iowa

    Since April 3, 2009

  • Maine

    In 2012, Maine voted in favor of a ballot amendment to legalize gay marriage.

  • Maryland

    The gay marriage bill was signed into law by Gov. Martin O'Malley (D) on March 1, 2012. Opponents later gathered enough signatures to force the issue back onto the ballot in November 2012, but voters rejected the effort against gay marriage.

  • Massachusetts

    Since May 17, 2004

  • Minnesota

    Same-sex marriage bill signed into law in May. Gay marriages will begin in August.

  • New Hampshire

    Since January 1, 2010

  • New York

    Since July 24, 2011

  • Rhode Island

    Bill passed in May. Law takes effect on August 1, 2013.

  • Vermont

    Since September 1, 2009

  • Washington

    On February 13, 2012, Gov. Christine Gregoire (D) signed a law allowing same-sex marriage ceremonies to begin on June 7, 2012. The process was delayed by gay marriage opponents who gathered enough signatures to put the issue up to a state vote in November 2012. They voted to approve it on Election Day.

  • Washington D.C.

    Since March 9, 2010

  • California

    The state initially began conducting gay marriages on June 16, 2008. On November 5, 2008, however, California voters passed Proposition 8, which amended the state's constitution to declare marriage as only between a man and a woman. In 2013, the Supreme Court ruled against that law, and the state shortly thereafter began sanctioning same-sex nuptials.