As near as I can tell, the main purpose for the bill is to give Rep. Huelskamp something to show the voters back home. It also provides a vehicle for other like-minded politicians to tout their anti-gay views for their constituents. The Huffington Post has the following Representatives listed as cosponsors:
... Its cosponsors include Republican Reps. Joe Barton (Texas), Jim Bridenstine (Okla.), Mo Brooks (Ala.), Paul Broun (Ga.), Jeff Duncan (S.C.), John Fleming (La.), Trent Franks (Ariz.), Louie Gohmert (Texas), Ralph Hall (Texas), Andy Harris (Md.), Randy Hultgren (Ill.), Sam Johnson (Texas), Walter Jones (N.C.), Jim Jordan (Ohio), James Lankford (Okla.), Mark Meadows (N.C.), Randy Neugebauer (Texas), Steven Palazzo (Miss.), Stevan Pearce (N.M.), Robert Pittenger (N.C.), Joe Pitts (Pa.), David Schweikert (Ariz.), Bill Shuster (Pa.), Chris Smith (N.J.), Steve Stockman (Texas), Tim Walberg (Mich.), Lynn Westmoreland (Ga.) and Frank Wolf (Va.)
Including Rep. Huelskamp himself, that makes the map of elected officials seeking to write their own prejudicial views into the US Constitution looking something like this:
The red area isn't limited to the Bible belt, even if it includes most of it. Nor is the red area limited to the South, again, even if it includes most of it. What it does show us is the place where we, the people for equality, need to do the most work. Here is where they are still electing anti-equality legislatures. Here is where we need the most help from the kind, decent, and caring people to help bring the entire United States into the light of freedom for all.