Legislation is making its way toward the Senate and House floors in Minnesota that would substantially reshape child custody negotiations for divorcing parents.

Right now, the presumption in divorce cases is that mentally fit and safe parents are each entitled to 25 percent custody and time with their children. The remaining 50 percent of custody rights are divvied up by a judge's ruling -- unless the parents reach agreement on their own. Friday morning, the Senate Finance Committee is scheduled to consider a bill that would increase that presumption to 40 percent -- meaning that only 20 percent of time with children would be left open for negotiation.

The change is being pursued in particular by advocates for fathers' rights, because of the history in divorce proceedings of mothers gaining larger shares of child custody. Supporters also point to the wealth of research showing that children are generally healthier and more well-adjusted when they have two involved parents. Opponents believe the change would be too restrictive for modern families, especially when some single parents aren't able to commit 40 percent of their time to raising their children.

It's a fascinating debate well-summarized in January by Patrick Thornton in an article for Minnesota Lawyer. On one side, in his article, was Molly Olson of the Center for Parental Responsibility:

On the other side is family law attorney Michael Dittberner, who said the bill would create a cookie-cutter approach to complex divorce proceedings:

The legislation was debated last session and appears on the fast track now. If the Finance Committee OKs the current bill, it's next stop would likely be the Senate floor. Underlying the whole debate is another number: 45.1% If divorced parents each have at least that much custody of their children, it is considered a joint custody situation. And that has ramifications on child support payments.

The custody presumption figure in the Senate bill has changed over time. At one point, it was 35 percent. The current legislation sets it at 40 percent. The House version of the bill takes a somewhat different approach, presuming 45.1 percent custody for parents but making allowances that would lessen the impact of that figure on child support and other issues. The bills also make allowances if one parent isn't pursuing joint custody, if the divorcing parents live far from one another, or if one parent is dangerous or abusive.

The House bill author is Rep. Peggy Scott, R-Andover, who has publicly discussed the cost and stress of a relative's divorce and the child custody negotiations. She believes a larger presumption of joint custody would compel divorcing parents to compete less and to work together more on their children's needs.