A speechwriter works directly with senior executives or leaders to determine what points, themes, positions, or messages the executive would like to cover. Speechwriters need to be able to accept criticism and comments on the different drafts of the speech, and be able to incorporate the proposed changes into the draft. Speechwriters have to be able to work on several different speeches at once, and manage their time so that they can meet strict deadlines for finishing the speech on time. Speechwriters must also be able to accept anonymity, because with few exceptions, speechwriters are not officially credited or acknowledged. This aspect creates a dilemma for historians and compilers of speech anthology; namely, when some poignant phrase gains popularity such as John F. Kennedy's "ask not what your country can do for you, ask what you can do for your country,". Should credit be given to the President, to speechwriter Ted Sorensen, or to both? Professional speechwriter Lawrence Bernstein writes: