Bill Hemmer played out the rest of the GOP presidential race on the map to give us an idea of just how close it will be in terms of Donald Trump reaching the "magic number" of delegates.

After Ted Cruz's big victory in Wisconsin, Donald Trump leads Cruz by a margin of 743 delegates to 517. 

The big question going forward is whether Trump will reach the 1,237 delegates needed to secure the nomination on the first ballot at the GOP convention. 

The projections are based on the average of the polls in the remaining states and leading political analysts' predictions, like Larry Sabato.

This scenario figures in big victories by Trump in New York, New Jersey and California.

Of course, Hemmer cautioned that these projections can change quickly as events unfold in the campaign. A few weeks ago, many thought that Trump would win in Wisconsin.

And he pointed out that there will be about 150 unbound delegates at the convention. Those are elected officials who can support whichever candidate they choose. 

If Trump is just short of 1,237 after the final primaries on June 7, there will be an intense month-long battle between Trump and Cruz to win over those delegates.

Watch the segment below.