WASHINGTON (AP) — Jeb Bush has long resisted pressure from supporters to run for president, but now the former Florida governor is signaling that he's open to the idea.

Bush is promoting a new book on immigration reform and not shutting the door on a 2016 presidential campaign. That's a significant change for the 60-year-old Bush, who comes from a long line of politicians. He's the younger brother of former President George W. Bush and son of former President George H.W. Bush.

Republicans and former advisers to Bush say he's making clear that he could be in the mix in three years and signaling to political operatives and donors they shouldn't count him out.

Bush has urged Congress to adopt immigration reforms and said Republicans need to do more to attract a diverse electorate.