This quote from former chess champion Garry Kasparov captures the significance of a Russian opposition leader's murder

Russian opposition leader Boris Nemtsov was shot dead in Moscow Friday, and many of his supporters including the former chess champion Garry Kasparov assume Vladimir Putin is to blame.

Kasparov - one of the world's greatest chess players and an ally of Nemtsov's who helped him organize protests against Putin - says Nemtsov's death shows Russia's leader is lying about his supposedly high approval ratings.

"If you have 86% support, why do you kill someone like Boris?" Kasparov said, according to the Associated Press. "He maybe can reach two million people online at best. A demonstration brings out a hundred thousand people at most. So if you are so confident, why do that?"

Nemtsov served as a deputy prime minister and a regional governor in Russia in the 1990s, when he helped put free-market reforms in place. Ukraine's president believes Nemtsov was murdered because he had evidence that Russia armed forces in Ukraine.

And Kasparov believes his ally's death is a sign that Russia viewed him is a threat and believes public support is flagging. The former chess champion's quote referenced a poll this month showing Putin's approval rating at a staggering 86%, according to CNN. Kasparov is not the only one who thinks Putin is fabricating his high approval ratings.

"That figure is made up," Ben Judah, author of "Fragile Empire: How Russia Fell In and Out of Love with Vladimir Putin," told CNN.