As you can see, the Conservative Index scores for the Cruz endorsers is significantly higher than for Rubio or Trump. The average for Cruz is 79.2 (25 endorsers), while Trump trails with 67.8 (4 endorsers) and Rubio brings up the rear with 66.3 (30 endorsers).
Cruz is publicly supported by 21 of the 71 Republicans in the State House, Rubio by 12 and Trump by 2. Rubio leads in Senate endorsements, with 18 of 39 Senate Republicans, while Cruz has 4 and Trump has 2.
Illustrating ideological similarities, all three presidential campaigns attracted nearly identical support in both houses of the legislature; Rubio's House/Senate score difference was only 0.3, Cruz's was 2.6, and Trump's was 3.5.