Her inevitability has nothing to do with polls, except of the super delegates to the Democratic Convention. Bill will pull in his chits and, given the fear factor that dealing with Clinton's has produced since their Arkansas days, she will get the 2025 delegates she needs for the nomination. She just about 10% of the way there anyway and we've only had one primary. She's the only one on the Michigan ballot so she will get that state completely without competition.
This is going to look alot like 1968 where McCarthy was the youth choice but old Humphrey got the party's nod.
Unless there is a serious setback on Super Tuesday, there is much ado about relatively unimportant primaries and caucuses.
Iowa and New Hampshire were important states for Hillary. If she loses in South Carolina, her prospects for a big sweep on Super Tuesday will be severely damaged. She can’t rely just on New York and California.