"It was important to her to honour the beauty of strong Black women and celebrate the unity that fuels their power. One of the best examples of that is the image of the female Black Panther," she said. "The women of the Black Panther Party created a sisterhood and worked right alongside their men fighting police brutality and creating community social programmes."
Giuliani said the move political and called for "decent, wholesome entertainment".
Others praised the performance for sending an empowering message to a long-aggrieved group.
Beyonce and her dancers also raised a fist to the sky, reminiscent of the black power salutes of the 1960-70s, made popular internationally by Tommie Smith and John Carlos, who raised their fists after winning gold and bronze at the 1968 Olympics.
Melina Abdullah, a Black Lives Matter activist and leader in California, said it was wonderful that artists like Beyonce "are willing to raise social consciousness and use their artistry to advance social justice".
Lakeyta Bonnette, a Georgia State University political science professor, said more and more celebrities like Beyonce were moving toward public activism.
In 2014, basketball superstar LeBron James and other NBA players wore "I can't breathe" Tshirts to their basketball games. "I can't breathe" were the last words of Eric Garner, a black man who died after a physical altercation with police in New York.
- Washington Post, Bloomberg, AP