On March 1st in Texas, Hillary Clinton scored a smashing victory in the Democratic primary -- doubling the number of votes of her competitor, Bernie Sanders. How did she do this? The exit polling shown in the chart below (from NBC News) gives us a big clue. She did it by carrying almost every demographic group by significant margins.
Bernie Sanders only won in one demographic group. He beat Clinton by 19 points among 18 to 29 year old voters. Unfortunately for him, that group only composed about 20% of the Democrats voting.
Clinton did very well among all other demographic groups --winning among men by 23 points, among women by 42 points, among those 30 to 44 by 18 points, among those 45 to 64 by 51 points, among those 65 & older by 75 points, among Whites by 16 points, among Blacks by 68 points, among Hispanics by 42 points, among college grads by 32 points, among those w/o college degree by 36 points, among those making less than $50k by 33 points, among those making more than $50k by 34 points, among liberals by 24 points, and among moderates by 46 points.
In other words, Hillary Clinton had a broad base of support in Texas -- and Bernie Sanders did not.
The chart below shows the percentage of the total vote by each group (red), and the percentage of each group won by Clinton (blue) and Sanders (green).