Hi,
"I'm going to make [my case] until we have a nominee, but we're not going to have one today, and we're not going to have one tomorrow, and we're not going to have one the next day," Clinton said Monday in Kentucky.
1. What's the meaning of 'make my case'? This is obviously not a lawsuit. 'To make your case'means 'to present your arguments/reasons'. She means 'I'm going to continue to tell the American people why I am the best person to choose as the Democratic candidate'.
2. What's the meaning of 'one tomorrow', 'one today', and 'one the next day'? 'One' is a pronoun here. It refers to nominee. She is saying
. . . but we're not going to have a nominee today, and we're not going to have a nominee tomorrow, and we're not going to have a nominee the next day,. . . ".
Best wishes, Clive