Presidential candidate Mitt Romney will speak to the National Rifle Association Friday, hoping to win over one of the key voting blocs for Republican politicians.

The former Massachusetts governor and the NRA have not always seen eye to eye.

When Romney ran for governor in 2002, the NRA gave his Democratic opponent a higher rating on gun-rights issues.

Criticism of gun rights laws have gained new momentum following the shooting death of unarmed Florida teenager Trayvon Martin.

The NRA strongly supported Florida's "stand your ground" law, which is now being called into question because of the case.

But a new Reuters poll shows that most Americans still support using guns when necessary.

About 87 percent of respondents support using deadly force to protect themselves from danger in their home. Two-thirds also back laws like "stand your ground" that permit the use of deadly force in instances of self defense.

The NRA is so important to GOP politicians that former Pennsylvania Sen. Rick Santorum, who is no longer in the presidential race, plans to keep his appointment to speak right after Romney.