And next here, to the Diane sawyer exclusive with Hillary Clinton. Tomorrow night here, one hour, no question off the table, and the interview comes just as a new ABC news/"washington post" poll... See More
And next here, to the Diane sawyer exclusive with Hillary Clinton. Tomorrow night here, one hour, no question off the table, and the interview comes just as a new ABC news/"washington post" poll reveals swelling support from democrats in this country. 7 in 10 democrats say they would back Clinton as their candidate if she runs in 2016. And this number tonight, across party lines, 67% of Americans polled see Clinton as a strong leader. And so tonight here, a preview. Diane asking, when will we all know if she'll be candidate Clinton again? Reporter: When are you going to decide whether you're running for president? You know, I'm going to decide when it feels right for me to decide. Because -- Reporter: Still by the end of this year? Well, you know, certainly not before then. I just want to kind of get through this year, travel around the country, sign books, help in the midterm elections in the fall and then take a deep breath and kind of go through my pluses and minuses about what I will and will not be thinking about as I make the decision. I will be on the way to making a decision by the end of the year, yes. Reporter: But probably not an announcement until next year? I -- I'm not positive about that, but I think, you know, the way I make decisions, that's probably likely. Reporter: I know it's a personal decision, but if you can do that -- if you can do it, you see the path and can do it -- do you have to do it? I have to make the decision that's right for me and the country, and -- Reporter: But is the party frozen in place, waiting for you to make it? No, I mean, no, people can do whatever they choose to do on whatever timetable they decide. Reporter: But are they disadvantaged waiting for you? Looking in your eyes every day? No, I mean bill Clinton started running for president officially in, like, September or October of 1991. So, no, I -- I just don't think that that's a -- you know, a real concern. People will do what they think is best for them and whether they choose to seek the presidency or not is very personal, for everybody. Reporter: And ultimately it has to be for you too? Right, absolutely. And tomorrow night, much more. Diane asks about benghazi, about Clinton's marriage, and if she has anything to say to Monica lewinsky. And grin gets a tour of Clinton's moment. It is rare access. Diane sawyer, one-on-one with Hillary Clinton, public and private, tomorrow night, 9:00 P.M. Eastern. And it comes on the eve of her new book, "Hardchoices." That's tomorrow night here. In the meantime,
This transcript has been automatically generated and may not be 100% accurate.