Hermeneutics became a heavily patrolled border.
Later fundamentalists ... became polemicists rather than apologists. The difference is subtle but crucial. Winning the war against modernism became more important than illuminating orthodoxy. Inerrancy came to represent not only a set of beliefs about creation or the reality of Jesus' miracles, but the pledge that human reason must always bow to the Bible. As fear of modernist theology and new science began to infect a wide range of Protestant churches, this new variety of fundamentalist deployed inerrancy as a simple shibboleth to separate the sheep from the goats. It was no longer a doctrine with historical roots or an ongoing debate among theologians ... Inerrantists intellectuals considered themselves something like Protestant Marines, a warrior corps whose confidence in the authority of scripture -- and commitment to taking the principle of God's sovereignty to its logical extreme -- anointed them as the Bible's shock troops, favorite sons, and truest defenders. (24)Partly, at least, this seems right. The struggle against the evils (as American fundamentalists saw them) of the Tübingen school and Schleiermacher made many stretches of middle ground impossible.
For example, Worthen writes about how some theologians of the Wesleyan Holiness tradition, including important figures in the early history of the Church of the Nazarene, rejected inerrancy. The ultimate revelation of God, they wrote, was not the Bible. The ultimate revelation was Jesus Christ, the Word made flesh. The Bible was to be thought of not as an authority but as a guide to the revelation of Christ.
It's "sufficiency," rather than inerrancy, was emphasized.
That position came to seem insufficient to many, though, in the defense against those who would deny the resurrection, the incarnation, and so on. The Church of the Nazarene's official statement that the Bible was inerrant to the extent that it showed "the will of God concerning us in all things necessary to our salvation" looked like an intolerable half-way measure (39-42).
It was exactly this middle ground, for example, that Francis Schaeffer tried to convince Karl Barth was impossible. Schaeffer thought Barth didn't realize, for one thing, how much aid and comfort his understanding of the Bible was giving to the modernist enemies of the faith. Or how much it was undermining the faith of the faithful. (Barth, for his part, was having none of it).
Middle grounds are just harder to maintain where there's a protracted struggle going on. Though "literalism" has never been as simple as it's made out to be, and inerrancy is never as cohesive as it's imagined, it is true that conservative Protestant doctrines about the Bible became more rigid during this time.