https://www.dailykos.com/stories/2017/11/30/1719909/-Jefferson-Sessions-won-t-say-if-Trump-asked-him-to-obstruct-the-Russia-investigation
"no matter how many times Sessions lies, it never seems to be enough to generate any response, or even concern, from Republicans in Congress. That includes failing to tell Congress that he had personally discussed the Trump campaign face-to-face with the Russian ambassador. However, in this case, it may be more than “memory problems” that keep Sessions from answering the question. Sessions is well aware that the reason Trump wanted former FBI director James Comey fired is because Comey refused to drop the Russia investigation. Sessions was in that up to his elfin ears."
