Consultant: you're welcome. as a first step, our team analyzed the other potential primary contenders. the reality is that with such a strong field, it is going to be difficult to gain the of votes necessary to avoid a runoff—unless you want to go negative from the start. and our opposition research team found plenty of ammunition to do just that.

A.Majority

Explanation:

...it is going to be difficult to gain the Majority of votes necessary to avoid a runoff.

The consultant here seems to be referring to a Runoff type of election where there are two rounds to voting. In this type of election, when no contender gets over 50% of the votes which is considered a Majority, the election goes to a second round with the highest 2 contenders or in some cases the contenders past a certain threshold then contending amongst themselves.

The Consultant is telling the candidate that the other candidates are quite strong so them getting the Majority vote required to avoid a second round will be tough.