After 40 years of marriage, including 24 in the political arena, Al and Tipper Gore announced their separation on Tuesday.

The news that the longtime couple were separating came in the form of an e-mail to their friends that shocked Washington.

“We are announcing today that after a great deal of thought and discussion, we have decided to separate,” the e-mail said, according to press reports. “This is very much a mutual and mutually supportive decision that we have made together following a process of long and careful consideration.”

Al and Tipper Gore ere known for having a strong and supportive marriage. They met at his high school prom and are said to have inspired the Hollywood romance “Love Story,” the sappy saga of a rich Harvard boy who falls in love with a girl from the wrong side of the tracks.

If their relationship was a love story, it was also a partnership typical of political couples.

Advisers described Tipper Gore as a sounding board for and confidante to the former vice president, whose own run for the presidency ended with the famous Bush v. Gore Supreme Court decision.

“She’s the first person he talks to about an idea,” Gore strategist Bob Shrum told Time in 2000, “and the last person he listens to before he decides.”

The most enduring image of the Gores’ relationship came during the 2000 Democratic National Convention in Los Angeles, when Gore gave his wife a famously long-lasting kiss that stunned convention watchers. It was a kiss dissected for days in the media, with some seeing it as an attempt to soften his famously stiff image.

When the Monica Lewinsky scandal rocked the country, the Gores’ happy marriage stood in sharp contrast to President Bill ClintonWilliam (Bill) Jefferson ClintonShould the Rob Porter outcome set the standard? Make the compromise: Ending chain migration is a small price to legalize Dreamers Assessing Trump's impeachment odds through a historic lens MORE’s philandering.

And during Gore’s own pursuit of the White House, he publicly distanced himself from Clinton, establishing his campaign headquarters in Nashville instead of Washington and picking then-Democratic Sen. Joe Lieberman (Conn.), who publicly criticized Clinton for his behavior, as his running mate.

After the Gores announced their separation on Tuesday, University of Virginia political science Professor Larry Sabato tweeted: “Could anyone have guessed that the Clintons’ marriage would last longer than the Gores’?”

Friends of the couple were quick to point out there were no allegations of an affair.

The Associated Press quoted Gore associates as saying the couple “grew apart.”

One of the Gores’ friends told the AP: “Their lives had gotten more and more separated.”

In an August 2000 Time profile, the Gores admitted they were different people. It’s “the old cliché about opposites attracting,” Gore said.

He described their marriage as “a communion [that] just became a lot deeper and broader to the point where I wouldn’t and couldn’t consider a major life decision without her deep involvement.”

Al GoreAlbert (Al) Arnold GoreJoe Lieberman: We’re well beyond partisanship, our national government has lost civility Trump doesn't start a trade war, just fires a warning shot across the bow Dems face hard choice for State of the Union response MORE, 62, and Tipper Gore, 61, were married at the Washington National Cathedral on May 19, 1970. They have four children: Karenna, Kristin, Sarah and Albert Jr., and three grandchildren.

After Gore lost the 2000 presidential election, the couple moved to Tennessee. He became an advocate for the environment, winning the Nobel Peace Prize in 2007 and giving lectures around the world. The documentary “An Inconvenient Truth,” based on Gore’s environmental talks, won the 2007 Academy Award for Documentary.

Tipper Gore, a co-founder of the Parents Music Resource Center, has spoken out against violence in the music industry. She also discussed her struggle with depression in 1989, after then-6-year-old Albert Jr. was struck by a car while crossing a street.

The Gores talked about going to counseling after the accident and how it strengthened their marriage.

Jordan Fabian contributed to this article.

This story was originally posted at 12:39 p.m. and updated at 7:39 p.m.