They absolutely were. The Nixon administration obviously defended themselves by claiming the investigation was full of bias and the Republican party (headed by Bob Dole at the time) also attacked them. Republicans in Congress were behind Nixon until it became obvious that the scandal was real.

The Post had to be extremely careful in their reporting because any mistake would be pounced on by the administration and its defenders as proof of their bias.

I recommend reading All the President's Men by Woodward and Bernstein or for a lighter read, Ben Bradlee's autobiography "A Good Life" which had a great chapter on it as well as a good one about the Pentagon Papers.