The headline from a new Des Moines Register- NBC News poll of Iowa is that former President Donald Trump still has a big lead in the Republican race. Among those likely to take part in the Iowa caucuses, Trump is at 43%, with Ron DeSantis and Nikki Haley tied for second place, at 16%. So, Trump has a 27-point lead, which is actually bigger than his lead in the last Des Moines Register poll in Augu…