Washington (CNN) After Donald Trump questioned Republican Sen. John McCain's status as a war hero, former Florida Gov. Jeb Bush quickly jumped to McCain's defense.

"Enough with the slanderous attacks. @SenJohnMcCain and all our veterans - particularly POWs have earned our respect and admiration," he tweeted on Saturday.

But that outrage was missing ten years ago, when a political group attacked another Vietnam veteran -- then-Sen. John Kerry, the Democratic nominee who sought to unseat Bush's brother, the incumbent president, during the 2004 election.

Instead, Bush praised Swift Boat Veterans for Truth, the group that lobbed attacks questioning Kerry's service record in Vietnam -- attacks McCain unequivocally criticized in 2004 as "dishonest and dishonorable."

When his campaign was asked if Jeb Bush saw a double standard, a spokesman rejected the premise.

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