Chris Christie was polling in the mid-single digits in the Republican presidential race and is hated by a majority of GOP primary voters over his fierce criticism of former President Donald Trump. So why could the former New Jersey governor’s decision to end his campaign dramatically scramble the race in favor of rival Nikki Haley, with unpredictable consequences for Trump? Even though Christie didn’t endorse Haley and even derided her in a hot mic moment on the way out, his departure will likely turn the Jan. 23 New Hampshire primary into a serious dog fight between her and Trump. Christie’s …