Trump could not win a two way race with either Cruz or Rubio

Stuart Rothenberger:

Trump Is More Vulnerable Than You Think

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Fox’s February 15-17 national survey found Trump at 36 percent on the ballot in the GOP’s national race and almost with a 2-1 lead over Ted Cruz, who was in second place. But when respondents were asked for a second choice, Marco Rubio and Cruz showed strong second-choice appeal. Trump did not.

That should not be surprising, given the controversy that Trump generates and his personal style.

It’s possible to win a primary with one-third of the vote, but it’s difficult to win a two-way or three-way race getting one in three voters. And that is a problem for Trump. His ceiling may prevent him from being the second choice of many Republicans.
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Most candidates who win multiple early contests have demonstrated broad appeal. In contrast, Trump remains a deeply polarizing candidate whose message obviously touches a certain kind of voter – one who is angry, wants a political revolution and is looking for a political strongman to mount a campaign against perceived enemies. That describes many, but not necessarily most, Republican voters.

The South Carolina exit poll found Trump doing very well among those voters who want a candidate who “tells it like it is” and well among those who want a candidate who “can bring needed change.” But he does very poorly among those respondents who want a candidate who “shares my values” and runs a weak second to Rubio among those who want a candidate who “can win in November.”
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He is among the weakest candidates still in the race.   He would lose to Cruz or Rubio in a landslide in a head to head race.  Cruz and Rubio would both beat Hillary Clinton and "Trump would not in a head to head race.