Karl Marx famously wrote that religion is the opium of the people. Religion, according to Marx, is intended to pacify populations and keep people from thinking about the injustice of the economic system under which they live. The same can be said of sports fandom. This is the common denominator between the two, religion and sports fandom. In an article in the New York Times titled "Sports Fandom: 'Opiate of the Masses,'" dated March 24, 2009, the author wrote:
Today’s idea: Sports fandom feeds a primitive human need to belong to a whole larger than the self. “Marx was wrong: The opiate of the masses isn’t religion, but spectator sports.”
Sports fandom does have a resemblance to religion. Fans are regular, punctual, have specific dress-codes, a common language, and anthems (for teams, in some cases). Ardent fans may actually be similar to religious fanatics; their team/sports icon is prioritized higher than other aspects of life, and they can be somewhat intolerant to criticism of their team/player. And most importantly, their actions are geared toward supporting, encouraging and pleasing their team/player. This is manifested by fans with colored faces, fans streaking on the ground (this has happened several times in Cricket and Tennis), etc.
Something similar is also observed in politics. Supporters of a particular party exhibit almost all the above-mentioned traits in order to support, please and encourage their own party or leader. In effect, political workers/supporters are akin to sports fans.
We observe the actions of ardent fans/supporters every day that remind us of religious fanatics. For example, fans write letters in blood, supporters threaten suicides to support their leader, etc. Both sports and politics have their share of quasi-religious activities.