That link is interesting. You can apply different filters to see different results.
For example, narrow it down to likely GOP primary voters (which, after all, is what counts) and Trump’s lead grows to 32%-13% over Bush, who is still in second—but just barely with Carson and Cruz following with 11.4% and 6.8%.
13+11.4=24.4 (Bush + Carson) 13+11.4+6.8=31.2 (Bush + Carson + Cruz)
Trump attracts more GOP primary voters than the next three candidates combined.