HAHAHAHA. It doesn't matter if he was successful or not to determine whether or not a crime was committed.
Here is the law:
18 USC S 1503
Whoever corruptly, or by threats or force, or by any threatening letter or communication, endeavors to influence, intimidate, or impede any grand or petit juror, or officer in or of any court of the United States, or officer who may be serving at any examination or other proceeding before any United States magistrate judge or other committing magistrate, in the discharge of his duty, or injures any such grand or petit juror in his person or property on account of any verdict or indictment assented to by him, or on account of his being or having been such juror, or injures any such officer, magistrate judge, or other committing magistrate in his person or property on account of the performance of his official duties, or corruptly or by threats or force, or by any threatening letter or communication, influences, obstructs, or impedes, or endeavors to influence, obstruct, or impede, the due administration of justice, shall be punished as provided in subsection (b).
Yates has already testified that she made trump aware of Flynn's vulnerability to be bribed and/or coerced. Talk about denying facts. Your buddy at NewsMax is the one who said he was considering firing Mueller.
Trump already admitted the firing of Comey was because of the Russia investigation. He cleared the room. That provides evidence to intimidate. They had already previously discussed his employment twice and trump had already told Comey he was doing a fine job. He mentions his employment again in this private conversation, clear evidence of quid pro quo. Under testimony by both Comey and Sessions, there was never a conversation addressing poor performance on the part of James Comey, therefore they never built a case for proper termination.