Story highlights "This is what leadership looks like," Clinton said on Instagram

"I wish you great happiness here," Bush wrote on Jan 20, 1993

Washington (CNN) Hillary Clinton posted a letter on Instagram from former President George H.W. Bush to her husband welcoming former President Bill Clinton to the White House, amid increased questions about whether Donald Trump will accept the results of a November election.

"This is what leadership looks like," Clinton said Thursday on Instagram.

In January 1993, President George H.W. Bush wrote President Bill Clinton a letter. This is what leadership looks like. A photo posted by Hillary Clinton (@hillaryclinton) on Oct 20, 2016 at 7:21pm PDT

Bush did not win re-election in his 1992 presidential race against the former president but wished Clinton "good luck."

"I wish you great happiness here," Bush wrote on Jan 20, 1993.

"You will be our president when you read this note," he added. "I wish you well. I wish your family well."

Former US Presidents George H.W. Bush and Bill Clinton smile as they leave the Oval Office on September 1, 2005 at the White House in Washington, DC.

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