With Donald Trump leading in the polls ahead of the Super Tuesday contests, many establishment Republicans have suggested that either Marco Rubio or Ted Cruz could stop Trump if the race were reduced to a one-on-one contest. Cruz and Rubio have also made this appeal, but are they right?
It is always hard to evaluate such "what-ifs," but to see whether Rubio or Cruz could challenge Trump in a head-to-head match-up, we used our latest NBC News|SurveyMonkey Weekly Election Tracking Poll to ask more than 4,200 registered Republican voters who they would vote for in a contest between either Trump and Cruz or Trump and Rubio. The poll was conducted during the week of February 22 through February 28, 2016, during the week leading up to Super Tuesday.
Our results suggest that unless something changes, Trump would emerge victorious in a head-to-head match-up with either Cruz or Rubio. When given only two candidates to choose between, Republicans preferred Trump over Rubio by an 8 percent margin, and they preferred Trump over Cruz by an even larger 13 percent margin. These results suggest that, at present, Trump's standing would not be diminished even if the race were reduced to a two-person contest.
Digging deeper, Trump's support in head-to-head match-ups with Cruz and Rubio is strong among important subgroups in the Republican Party.
Among white evangelicals, both Cruz and Rubio hold only a very slight lead over Trump. However, Trump maintains a double-digit lead among non-evangelicals in a head-to-head against either Rubio or Cruz. Against Cruz, his lead is more than 20 percent.
Looking at the support by voters' ideology reveals broad support for Trump, especially among self-described "moderate" and "conservative" Republican registered voters. In fact, Trump commands a majority of support against either Rubio or Cruz in a head-to-head match-up among the two groups. Only among "very conservative" voters does Trump lose by a decent margin to Cruz and Rubio — Cruz beats Trump by 20 percent among "very conservatives," but Rubio's lead over Trump is high single digits.
While a lot can change in a campaign, it is not obvious that a consolidation of the Republican field will substantially alter the GOP race. Based on our latest poll of more than 4,200 registered Republican voters, even if the Republican race were reduced to either Trump versus Rubio, or Trump versus Cruz, Trump would emerge victorious. This suggests it will take more than candidates dropping from the field to challenge Trump's lead.
The NBC News|SurveyMonkey Weekly Election Tracking poll was conducted online from February 22, 2016 through February 28, 2016 among a national sample of 30,294 adults aged 18 and over, including 26,859 who say they are registered to vote. Respondents for this non-probability survey were selected from the nearly three million people who take surveys on the SurveyMonkey platform each day. Results have an error estimate of plus or minus 1.0 percentage points. A full description of our methodology and the poll can be found here.