There is a very real difference between supporting the right of an unborn child to live, and supporting the right to kill a violent criminal. I'll give you a hint, one of them hasn't made any choices, and the other has made very very bad choices.

So, because I think every child has the right to live, I should foot the bill for those people who can't afford to have children and do anyway?

I'm sorry, but I should not have to pay for stupid people's stupidity. They also should have the right to kill someone just because it makes their lives easier. It's really that simple.

By the way I do not support capital punishment per se, but I do understand the viewpoint.

In my ideal situation, people who cannot live in society (violent criminals) are removed from it and forced to repay their debt: I.e. they generate some benefit for society, and don't just put a drain upon it. Noone ever gets the right to commit murder, no matter how convienient it might make their lives (I'm exluding war here). People who cannot afford to have children, or cannot take care of them (lack of ability to manage their own lives is a strong indicator) do not have children.

The last part is by a wide margin the toughest, but in a purely pragmatic viewpoint (amoral) the best method might be removal of subsidies, a higher infant mortality rate, and very strict punishments (even more so than now) for neglect etc.