As the newly anointed GOP frontrunner, Newt Gingrich is facing increased scrutiny about his record, policy proposals and temperament. But so far, Gingrich’s age – he will turn 69 next summer – has virtually escaped notice.

This marks quite a change from the last presidential campaign, when then 72-year-old John McCain faced persistent questions about his age and health. And in 1996, there was widespread concern over 73-year-old Bob Dole’s age. Ronald Reagan confronted perhaps the toughest questions about his age, mostly during his reelection campaign in 1984, but also in 1980. Reagan turned 69 a few weeks before that year’s New Hampshire primary.

McCain’s age, in particular, was on the mind of voters during the 2008 campaign. In February 2008, after McCain won a series of pivotal GOP primaries, voters were asked which single word best described him: “Old” was by far the top response, outnumbering mentions of “honest,” “experienced” and “patriot.” At that time, roughly a third of voters said McCain was too old to be president, which was comparable to the percentage expressing that opinion about Dole in 1996.

Certainly, McCain’s health problems may have contributed to concerns about his age. He had survived three bouts with malignant melanoma, the deadliest form of skin cancer. And McCain still visibly struggled with the serious injuries he had suffered as a POW in Vietnam nearly 40 years earlier.

By all appearances, Gingrich is healthy and vigorous. But there are other reasons why age may end up being less of an issue for the soon-to-be septuagenarian. For one thing, he would not be breaking any age barriers. In 1984, Reagan had to overcome the stigma of being the oldest presidential candidate in the nation’s history. Dole and McCain had the unwelcome distinction of being the oldest to run for a first term. Gingrich’s age also does not particularly distinguish him from current GOP candidates. At 64, Mitt Romney is only four years younger than Gingrich; at 76, Ron Paul is eight years older.

Moreover, the population itself is aging. The fastest-growing segment of the population over the past decade, according to the latest Census, is people age 45 to 62. The next fastest growing segment? Those 62 and older.

The Republican base also is getting older. A 2009 analysis of party identification trends by the Pew Research Center found that the percentage of all Republicans who are 50 and older increased by 10 points – from 36% to 46% – between 1990 and 2009; the percentage of Democrats 50 and older held steady over this period (44% in 2009).

In its most recent political typology, released in May of this year, Pew Research identified a group of Staunch Conservatives, who are highly politically engaged and thus are likely to play a key role in the upcoming GOP primaries. And with 61% of this group 50 and older – making it by far the oldest of the nine typology groups – they would be unlikely to view Gingrich’s age negatively.

Even in a general election against Barack Obama, who will turn 51 in August, it is hard to imagine Gingrich’s age making much difference. Certainly, to young adults, Gingrich might seem old in comparison to Obama. A 2009 report by the Pew Research Center’s Social and Demographic Trends Project found that more than half of those under 30 say the average person becomes old even before turning 60. But that view is not shared by older age groups: For those in their 30s and 40s the mean age at which someone becomes “old” is 69. It is even higher –in the early 70s – for those in their 50s or older.

Gingrich is not likely to capture a majority of the youth vote, whether they perceive him as old or not. Younger age groups have voted substantially more Democratic than other age groups in every election since 2004 – when they supported 60-year-old John Kerry over 58-year-old George W. Bush. But if Gingrich wins the nomination, older voters, who will be more in play next November, are likely to view his age as nothing more than a number.