Reading between the lines, I sense that this prospective candidate may lean conservative (right). You said along mainstream lines (moderate to liberal in the USA) and that "you dont want to be seen as sharing his opinions" Therefore, even if his politics leans right, I suspect this may not be mainstream conservative, but hard , far right wing.
If the comments are objectively offensive / demeaning, such that you think he would make others in the workplace uncomfortable, I would let the project manager know, and maybe your n+1 boss. Generally comments of this type fall into categories of discrimination towards protected groups by law, harassment, incitement to unlawful violence, or promoting harm to others etc. I am fairly active on social media such as twitter or facebook and I have seen commentary that are undoubtely and objectively offensive, and comments which are mereely unpopular but not causing offense / objective harm.
If on the other hand, these comments are merely his personal opinions that be unpopular / distasteful, but not objectively offensive, then I would let him be, and leave the subject matter alone.
In any case, dont push your opinion either way, but just state your concerns if they could hurt the company via being objectively offensive.
Take a step back and evaluate the prospective candidates activity not through the lens of your personal views, but whether they could make others uncomfortable, and are objectively offensive