Michelle, firstly I have to say that I have never applied for an internship to a senator! However I have in my long career of over 30 years conducted thousands of interviews of young people, including those with no experience. I hope my tips will help you. All the best!
Firstly, most interviewers, particularly when they interview freshers, are looking more for attitude, aptitude and how she answers, even more than what those answers are. An internship interview should not be too different from a job interview in my view, particularly if the expectation is that it will grow into a job if all goes well.
In most interviews the interviewer looks for a candidate who is intelligent, articulate and quick-witted. Someone who is agile and mentally alert. And most importantly someone who is honest and has high integrity. Sometimes they are looking for people who are highly organised and will look for evidence in your resume and your appearance to show that you are. Sometimes people are looking for someone who is vey creative and will look for such evidence. If they are looking to hire for a difficult, client-facing position, they will look for someone who is always relaxed and pleasant, even if the questions are tough.
So it would be good to get as much background info as you can about this person you re going to work for and what qualities the job will require and prepare accordingly.
Re clothes I would always advise formals for an interview. Well ironed and simple but elegant, with no frills and ornaments. Well-polished shoes, neatly combed and held hair – in short everything that says you are neat and minimalistic. Subdued hues of make up – nothing obvious. Nothing that jingles☺
Make a list of typical questions (some are given below but there are many sites online which will give you more). Make sure you are honest in every answer. work the answers in your mind until you are clear what you are going to say. That will ensure you don't stammer or fumble when answering them. Make sure you are smiling throughout the interview – but not grinning or being facetious☺
At a first interview you will normally be asked simple things like:
1. Tell us something about yourself. (Wonderful opportunity to take the interview the way you want to by stressing on those aspects you would love to talk about.)
2. Why did you choose (the subject of your study) to study?
3. How do you find it correlates with this position?
4. Why do you want to take this position?
5. Why should we consider you above the others?
6. What are your key strengths? Weaknesses?
7. Tell us about an experience (that you cherish/ want to forget/ succeeded at/ failed at/ learned from etc.)
8. What are your views on (issues related to the political affiliations of the senator)?
9. What are your future plans?
There will be questions directly related to the role you are seeking to play and the issues related to it – which I am sure you will figure out by studying the position clearly. Make a list of those questions too and prepare yourself with answers. Never memorise the answers! But prepare so you are not caught off guard and do not have to think too hard to get an answer. All the best Michelle! ☺