William G. Mayer

William Mayer, a political science professor at Northeastern University, told Factcheck.org that the Democratic convention delegate rules allow for pledged delegates to vote for a new candidate. “You are kind of encouraged to vote for the candidates for whom you were elected – but ‘in all good conscience’ you could vote for someone else,” Mayer said.

William Mayer, a political science professor at Northeastern University, told Factcheck.org that the Democratic convention delegate rules allow for pledged delegates to vote for a new candidate. “You are kind of encouraged to vote for the candidates for whom you were elected – but ‘in all good conscience’ you could vote for someone else,” Mayer said.

Counting Iowa, New Hampshire, South Carolina and Michigan, Trump has won a little over three-fifths of the total combined vote so far. That slightly exceeds the share that Reagan won in 1980 and equals the percentage George W. Bush won in 2000, according to results compiled by Northeastern University political scientist William Mayer. 

“If you want to win, you have to get a significant percentage of the swing voters,” said William G. Mayer, a professor of political science at Northeastern University who has written extensively about swing voters. 

In 2008, after winning Iowa but losing New Hampshire and Nevada, Mr Obama enjoyed a huge win over Mrs Clinton in South Carolina including 78 per cent of the black vote, according to data compiled by William Mayer, a politics professor at Northeastern University.

In fact, winning in New Hampshire increases a candidate’s expected share of the total primary vote by 27 percentage points, according to William Mayer, a political scientist at Northeastern University.