Struggling With a Scene in My Novel...Any Suggestions????

Hello all,
       I hope your Thanksgiving went well. This year my family spent the holiday with my brother, Kevin, and his clan. We ate, drank and were merry. However, it never ceases to amaze me how two people that were raised in the same household could be so very different. My brother likes Nascar, I like the opera, he fries the turkey, I prefer it baked (well, I used to, I have to admit fried is pretty good too:)) Although it would be a stretch to say that we embraced each other's differences, we were able to tolerate them for a day or two. I enjoyed my time with Kevin very much, but needless to say, I was definitely ready to return home the day after Thanksgiving.
       Unfortunately, due to the hectic holiday schedule, almost a week has passed since I last worked on my novel. When I returned to my writing this morning, I struggled with a bout of: is this part of the story credible and realistic… is it necessary? My husband says yes, because the chapter develops my villain. Before telling you about the scene in question, I think it is important to provide a little background info. Long and short of it, the V.P. mysteriously and suddenly contracts terminal cancer and steps down. In turn, the President invokes the 25th Amendment to the Constitution (similar to Spiro Agnew's situation) and nominates my villain to the V.P. position. This leads to the scene in question….which takes place at a White House cocktail party to celebrate the new nominee.
      Although I've researched White House protocols, I'm not sure if some of the scenes are realistic. For example, since the V.P. is the guest of honor, he enters the party after the Commander and Chief is announced. Question: is it acceptable for the V.P. to enter after the President under any circumstances? Also, given the situation, i.e., nomination takes place because the V.P. is ill, would the President choose to celebrate the V.P.’s nomination, or would he have a small and intimate dinner instead? In the whole scheme of things, White House protocols may be a minor issue , but I want my writing to be credible.
       In an effort to resolve my problem, I e-mailed the protocol office at the State Department to determine how such a situation would be handled. But alas, I have not received an answer. I contacted a couple of staffers for federal senators that I'm acquainted with, but neither of them knew how such a situation would be handled either. If any of you have the answer, or know where I can find it, or have suggestions, I would welcome them about now. Until my next post… happy writing.