From my experience a key question to ask is: What would the eventual law say? Will it make it a federal felony to possess an encrypted phone? Or a federal felony to sell one?
The FBI endorsed H.R. 695 the last time around, which would have done the latter. Read it for yourself:
"Whoever, after January 31, 2000, sells in interstate or foreign commerce any encryption product that does not include features or functions permitting duly authorized persons immediate access to plaintext or immediate decryption capabilities shall be imprisoned for not more than 5 years, fined under this title, or both..."
"After January 31, 2000, it shall be unlawful for any person to manufacture for distribution, DISTRIBUTE, or import encryption products intended for sale or use in the United States, unless that product-- `(1) includes features or functions that provide an immediate access to plaintext capability... requiring any person in possession of decryption information to provide such information to a duly authorized investigative or law enforcement officer..." (http://thomas.loc.gov/cgi-bin/cpquery/T?&report=hr108p4&dbna...)
Note the distribution ban above. That would have hit open-source and free software projects.
Put another way, implementation details matter. A lot of voters might agree with the general proposition that law enforcement should have a way to snoop on terrorists|child pornographers|drug kingpins. They might not agree that a 14-year HN reader with a forked version of Android|AOSP on Github should go to prison for 20 years because he dared to distribute an unencrypted OS.