Impeachment? LOL

President: "I hope you can let this go."
FBI Director: "I think {Flynn] is a good guy."

Was there an order to end the investigation? No. Was there an obstruction of an investigation? No. Neither did the president ask that the investigation be halted, nor was Comey pressured to do so. All that happened was what happens in Washington 1000 times a day: you help me, I'll help you. 

Trump's haters should know that it's foolish to underestimate your enemy.