Former Florida Gov. Jeb Bush is bringing out the big guns for his next donor summit, turning to his father and brother to headline the event in Texas this fall, according to a copy of the invitation. Former Presidents George H.W. Bush and George W. Bush will be the big draw at the third major-donor conference Jeb Bush has organized to raise money for his 2016 White House bid. The Houston gathering, dubbed the “Jeb Celebration,” illustrates the pros and cons of Jeb Bush’s famous bloodline because it is sure to draw legions of donors loyal to his dad and...