Methodists such as George W. Bush and Dick Cheney who are conservative and Republican tend to agree on one set of social principles. Methodists such as George McGovern and Hillary Clinton who are liberal and Democratic tend to agree on another set of social principles. People in the pews tend to choose pastors and congregations that match their own political and partisan interpretations of scripture.
I've heard Methodist leaders on both sides of the sanctuary aisle lament that the church has been captured by the culture. I think it's worse than that. I think the church has surrendered to the culture.
First of all there are not different social principles. There is just the Social Principles of the United Methodist Church, first written in 1910, and affirmed at the united conferences of 1939 and 1968. The issue of "implementation" isn't one of political ideology because they aren't about politics, but carrying out Wesley's teaching that we are to be about serving the Kingdom of God through acts of justice in the world.
By adding the frame of the whole "people in the pews", and describing the way "people pick" clergy and congregations - wow. Ours is an episcopal polity, in which clergy serve a yearly term, appointed each year by the bishop with the advice of a cabinet of what were once known as presiding elders and are now known as District Superintendents. Local congregations do not "pick" clergy. They may or may not choose to support a particular appointed clergyperson, but that is not the same thing.
Finally, as the authors of the report clearly state, while the Presidential library clearly violates not just the Social Principles, but several other paragraphs of our Discipline, the contract between SMU and those who are proposing the library is binding, limiting the recourse of those opposed. Therefore, the issue isn't about politics. It's about the law. Our denominational law, the separation of church and state, and our integrity as a denomination.
It would be nice if a publication as reputable as Newsweek would publish something by someone who displayed at least passing familiarity with the structure of a church he was writing about.
Finally, George McGovern was and is a far better United Methodist than George W. Bush. See, part of the membership pledge is that one will support the local congregation through prayer, presence, gifts, and service.