Trump, needs this state. Good that he is leading in the polls!
While I wouldn't say he exactly needs it, it definitely expands his path to victory. If he manages to flip one of the states in the rust belt like PA, then he wins the election.
Assume Trump wins AZ, FL, OH, and IA - that puts him at 244 EVs. Flip PA (which I think is a sleeper state), and he's at 264. From there, he can get to 269 via a variety of ways (listed by most likely);
1) NC - 279
3) VA* - 277
2) NV - 270
3) NH plus 1 (even one delegate from Maine would do) - 269
4) Win literally any other state (CO the next likeliest, but also long-shots like MI and WI)
If he doesn't flip PA, his paths are (listed as most likely);
1) NC, VA - 272
2) NC, NV, NH - 269
3) CO with various combinations of NC, VA, NV, or NH (not all states needed for 269)
* While most would say VA now leans slightly dem, I believe it is a true 50/50 tossup this election. The reason Obama over-performed there twice was because of the high black population turnout. However, even then, the total vote almost exactly matched the national vote in the state - a true bellweather. Will black turnout be as high for Clinton as for Obama? I highly doubt it.