Senate Republicans are facing increasing criticism for ducking public scrutiny as they craft legislation to roll back the Affordable Care Act with little input from outside experts, patients, physicians and others most affected by healthcare legislation.

The GOP’s secretive process marks a sharp departure from the traditional way the Senate has developed large, complex bills, which are often debated for years with multiple committee hearings to ensure broad input and careful analysis….

Rutgers University professor Ross Baker, who has spent decades studying Congress, said lawmakers have traditionally used committee hearings and public debate over legislation to help educate voters and build support for complex and controversial legislation such as the civil rights bills of the 1960s.

That is what makes the current GOP effort so remarkable, he said. “I can’t think of another piece of legislation of this scope and magnitude that affects so many people that has been drawn up behind such a dense veil of secrecy.”

Don Ritchie, historian emeritus of the Senate, said not since the years before World War I has the Senate taken such a partisan, closed-door approach to major legislation.

A century ago, Senate Democrats, at the urging of President Woodrow Wilson, drew up major tariff reforms while shutting out Republicans. But when Democratic leaders tried that again when they had large majorities during the Great Depression, rank-and-file senators revolted. It hasn’t happened since, he said.

Even the deeply partisan debate over the development of the Affordable Care Act, which ended with Democrats alone voting for the bill, had Republicans at the table for much of the process.