Troy Davis protesters on Wednesday
Hundreds of people protested in Atlanta on Wednesday on behalf of Troy Davis, who was executed for the 1989 killing of police officer Mark MacPhail.

Anger is growing in the U.S. over the execution of Troy Davis, 42, who was killed Wednesday September 21 after facing execution four times in the past four years for being convicted for the murder of a policeman, despite serious doubts about his guilt, with supporters of Davis now turning to Obama for answers.

His conviction hinged on nine witnesses as no physical evidence linked him to the crime and despite attempts to overturn the death sentence after seven of the witnesses later recanted their testimony, after saying they had either been coerced by police or realised they had identified the wrong men.

Despite three stays of execution in 2007, 2008 and 2009 (the final stay was ordered by the Supreme Court after Davis filed for habeas corpus) and over 660,000 petition signatures for clemency, including former President Jimmy Carter, Archbishop Desmond Tutu, Pope Benedict XVI and Jesse Jackson, Jr, the state still ordered for Davis to be executed.

Former FBI director William Sessions, who also called for Davis' execution to stop recently, wrote "It is for cases like this that executive clemency exists."

Despite calls for President Obama to react and address the affair, the head of Washington has instead preferred to remain silent, focusing on trying to prevent the Palestinian UN statehood bid, which could now have negative domestic repercussions for him.

For many of Davis supporters, the case is simple, as they say that despite no evidence he killed Mark MacPhail, for the authorities the case can be resumed as that of a black man convicted of killing a white police officer and that this fact alone will trump all others.

Commenting on accusations of racial discrimination, Georgia Congressman John Lewis declared in September 2008 "Race is everything in this case."

Protesters are now angered that despite hundreds of thousands of petitions sent to the Board of Pardons and Paroles on Davis's behalf, the lesser-known case of Duane Duck became a top priority.

Duane Buck, who admitted to killing two people, was scheduled to die in Texas on September 15.

The case produced anger when during his trial a state psychologist told jurors that Buck posed "future dangerousness" because he is black, and the convict was later on to death row, but his life was later on spared, at least for now.

But Davis supporters now question why Buck who had admitted being guilty of murder managed to avoid execution when Davis who had kept on proclaiming his innocence until the last minutes was killed.

The death penalty is becoming more and more controversial in the U.S. as innocent people are said to have died on death row and this year, the state of Illinois, where a Republican governor once commuted 167 death sentences citing doubts over "the fairness of the death penalty system as a whole," became the fourth state in five years to abolish it.

The country however is still divided as Republicans gathered at the Reagan Library cheerfully applauded Governor Rick Perry's unprecedented execution record which now stands at 235 people.

While many Republicans do not hesitate to give their view on the topic, protesters who now want the abolition of the death penalty throughout the U.S. are increasingly fed up with the Democrat's inability to efficiently tackle the debate, only saying the punishment should be reserved for the "worst of the worst."

Obama's unwillingness to openly give his view on the Davis' case is now bringing back bad memories for anti-death penalty Democrats who recall how they felt betrayed when President Bill Clinton who once attended the execution of a mentally disabled man while on the campaign trail in 1992, went on to sign the Anti-Terrorism and Effective Death Penalty Act, which considerably limited prisoners' rights to appeal their sentences.

After popular pressure concerning the president's lack of involvement, Press secretary Jay Carney issued a statement saying that although Obama "has worked to ensure accuracy and fairness in the criminal justice system," it was not appropriate for him "to weigh in on specific cases like this one, which is a state prosecution."

This statement however did not calm the thousands of people who called for Davis's execution to be adjourned and it seems that the case has now convinced a lot of Americans that death penalty has become a relic of injustice. As the election approached Obama might have tried to play it safe by not getting involved in the Davis case but many of his voters will feel betrayed by a man who said he would promote justice and inclusion.