But the answer is simple: Republican voters like Trump; Ryan risks losing the support of rank-and-file GOPers if he hits Trump too hard.
Trump is more popular among Republicans right now than Ryan is. In the most recent YouGov poll, for example, Trump’s net favorability rating (the percentage of respondents who rate him favorably minus the share who have an unfavorable opinion) among Republican primary voters was +36 percentage points. Ryan’s was just +16 points. Perhaps more telling is that Trump’s “very favorable” rating among this group is 34 percent, while Ryan’s is only 13 percent.
http://fivethirtyeight.com/features/paul-ryan-needs-trump-more-than-trump-needs-ryan/
Trump is more popular among Republicans right now than Ryan is. In the most recent YouGov poll, for example, Trump’s net favorability rating (the percentage of respondents who rate him favorably minus the share who have an unfavorable opinion) among Republican primary voters was +36 percentage points. Ryan’s was just +16 points. Perhaps more telling is that Trump’s “very favorable” rating among this group is 34 percent, while Ryan’s is only 13 percent.
http://fivethirtyeight.com/features/paul-ryan-needs-trump-more-than-trump-needs-ryan/