Mankind is selfish and our first use of clones was to rape them of their body parts and use it to replace ours. If its considered life, then we're screwed. If a clone satisfies all the definitions of life, then we have to go through a long identification process. He would need to be fingerprinted, measured, social securitied and all that good stuff. But more importantly, we have to remember this isn't a twin.
Twins are lookalikes, and maybe thinkalikes to a degree.
But a clone is an exact copy of you. It's going to want to live in your house, mess with your wife, and take your children to the park. If a clone satisfies all the definitions of life, then we can't use them for war. And we can't tell them to test our new theories in the lab. We can't tell them to work our job while we are on vacation.