The collection includes t-shirts, tank tops, bags, stickers, a drawstring backpack, buttons, rally signs and temporary tattoos.
The merchandise is adorned with the transgender pride flag or the colors of the rainbow flag. One design hails the 50th anniversary of Stonewall, the New York City riots credited with ushering the modern LGBT rights movement.
The designs use an 8 color version of the rainbow flag that includes brown and black to show support for people of color.
Slogans that appear on the merchandise include “BOOT EDGE EDGE” and “Win the Era” in rainbow colors.
Buttigieg, the openly gay mayor of South Bend, Indiana, has rocketed to third in the polls behind former Vice President Joe Biden and Vermont Senator Bernie Sanders, though Biden maintains a commanding lead.