Wednesday, he called for a national debate about embryo research before scientists make the practice more commonplace.
Embryo research, he said, "is breaking a medical taboo that embryos would not be created simply for research. ...that taboo against creation of human embryo has been broken.
"This is something I've been warning about publicly and privately," Brownback said. "This really points out the need for us to look at this in very complete fashion before it rolls along and develops with no regulation, no regard, no review.
"What is an embryo?" Brownback asked. "A person or property? It looks like this question will be forced on us by the medical community sooner rather than later."