PRINCETON, NJ -- Less than half of Americans know enough about Florida Sen. Marco Rubio and Ohio Sen. Rob Portman -- two possible candidates for the Republican vice presidential nomination -- to have an opinion about them. Among those who do have an opinion, Rubio is viewed more favorably than unfavorably, while Portman's image is mixed.
As the presidential campaign moves into the summer months, presumed Republican nominee Mitt Romney's selection of his vice presidential running mate will likely be the next major event to take place, either before or during the Republicans' Aug. 27-30 national convention in Tampa, Fla. Romney has given no indication of whom he is considering, and observers have developed various lists of possibilities. John McCain surprised the world with his choice of Alaska Gov. Sarah Palin in 2008, underscoring the assumption that no one really knows who is under consideration until the announcement is made.
Still, Rubio's and Portman's names generally appear on most lists of potential vice presidential candidates. Both are lawyers, and both have sets of characteristics that would make them appealing nominees. Rubio is of Cuban heritage, with the potential to help the Romney ticket among Hispanic voters, and is from the crucial swing state of Florida. Portman is also from a crucial swing state. Before he became a senator, he served in the House of Representatives, and as a U.S. trade representative and as director of the Office of Management and Budget under President George W. Bush.
At this point, Rubio is twice as well-known as Portman, with 44% of Americans in the May 7-10 USA Today/Â鶹´«Ã½AV poll able to give an opinion of him -- compared with only 22% of Americans who have an opinion about Portman.
Both Rubio and Portman have already developed partisan images among Americans who know them. Republicans' and independents' opinions of Rubio break positive by 42% to 11% and 27% to 14%, respectively, while Democrats are more negative than positive about him, with 8% favorable and 28% unfavorable. Portman's image follows the same pattern, although fewer Americans of any partisan affiliation have an opinion of him.
There are too few Hispanics in the survey for Â鶹´«Ã½AV to give meaningful estimates of their views of Rubio.
Implications
Sen. Marco Rubio at this point in his political career is essentially unknown to over half of Americans, while Sen. Rob Portman is unknown to over three-quarters. This lack of national name recognition is not unusual for the majority of members of Congress and the Senate, as well as most governors, and is typical of several eventual vice presidential nominees when Â鶹´«Ã½AV first asked about them.
Sarah Palin was unknown to 71% of Americans when Â鶹´«Ã½AV first asked about her in August 2008. Fifty-five percent of Americans didn't have an opinion about Joe Biden and 44% about Al Gore when Â鶹´«Ã½AV first asked about them in April 2007 and July 1992, respectively.
If either Rubio or Portman is selected as Romney's vice presidential nominee, the sudden scrutiny and intense public spotlight that will ensue have the potential to move their image in either a positive or a negative direction. In 2008, for example, Palin's image became progressively less positive as she became better known. In a Sept. 5-7, 2008, Â鶹´«Ã½AV survey, 53% of Americans viewed her positively, compared with 28% who viewed her negatively. By early October, her image was 51% favorable/41% unfavorable, and just before the election, her image had moved into negative territory, with 42% viewing her favorably and 49% unfavorably. Joe Biden's image in 2008, on the other hand, remained more positive than negative right up to the election.
Â鶹´«Ã½AV will track the trend in the image of the eventual Republican vice presidential nominee once Romney makes his choice later this summer.
Survey Methods
Results for this USA Today/Â鶹´«Ã½AV poll are based on telephone interviews conducted May 10-13, 2012, with a random sample of 1.012 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia.
For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±4 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample includes a minimum quota of 400 cell phone respondents and 600 landline respondents per 1,000 national adults, with additional minimum quotas among landline respondents by region. Landline telephone numbers are chosen at random among listed telephone numbers. Cell phone numbers are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, and phone status (cell phone only/landline only/both, cell phone mostly, and having an unlisted landline number). Demographic weighting targets are based on the March 2011 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
View methodology, full question results, and trend data.
For more details on Â鶹´«Ã½AV's polling methodology, visit .