A bit of selective bias that couldn't be further from the truth.
Shapiro's allegiance is to the Constitution and to conservative values. He often talks about religion and Constitutional law. Yet, I've never heard him place one over the other because he's the first one to admit that there's a distinct role for one vs the other. It's actually the thing that he frequently rails about - that people do try to use feelings and personal values to subvert established law. He keeps a strict separation between his Orthodox beliefs and his discussion of the law.
(I can also speculate about why someone would point out that an Orthodox Jew would let his religious views supersede a rigorist interpretation of the Constitution)
I also don't buy the partisan claim, especially in comparison to a Jon Stuart, who is an overt partisan to the Democratic party. I've never heard Shapiro act as a shill for the GOP, and he's held a very consistent view and does not shy away from criticizing either party or the individuals. When was the last time you've heard anything but token critique of the left from a Jon Stuart?
Shapiro's criticism of the leftist activism is rightfully framed in fascist colors, because that's what the majority of the Resist tactics are. It is not a peaceful resistance that was commonplace in American politics, but has taken on a greater confrontational/violent element of European opposition playbook that's steeped in anarchist/fascist roots. There's very little in the latest incarnation of left-liberal dissent that is truly American.