Republican presidential contender Jeb Bush on Saturday rebutted Donald Trump’s relentless mocking of him as a “low-energy” candidate, telling congregants of a Westhampton Beach synagogue of 16-hour campaign days crisscrossing the country. “If you’ve been following the campaign, there’s a candidate that says that some candidates are idiots and some candidates are this and some candidates are that,” Bush said at the Hampton Synagogue. “I’ve been apparently the candidate that has low energy. So I’ll just give you a little taste of the low-energy candidate’s life this week.”