Older people are once again flexing their muscles at the ballot box, sending politicians scampering for cover at the mere mention of tampering with Medicare.

Yet if seniors wield disproportionate political influence, in media they remain victims of an age-old (or make that “old age”) divide.

CBS has argued for years that the over-50 audience shouldn’t be ignored, primarily because most of its audience is over 50. Now, with the auds of other networks getting older, there’s been furtive movement in that direction elsewhere, such as NBC coining the term AlphaBoomers to describe an active group that could potentially push the upper reaches of TV’s demographic landscape to 64. (Of course, that would still overlook more than half of Fox News Channel’s audience, but it’s a start.)

If there’s any urgency surrounding the media’s interest in seniors, however, it’s not readily apparent — despite a recent Wall Street Journal piece noting that overall TV viewing among adults 18-49 has slipped in consecutive years, down 2.7% from two seasons ago.

At the same time, signs of the disparity between what older viewers like and the TV tastes of younger folk have yielded some rather striking examples.

One of the more jaw-dropping demonstrations occurred during the May sweep, when CBS’ latest “Jesse Stone” movie, starring Tom Selleck, delivered an impressive 13.7 million viewers overall, but just 1.7 million of them in the 18-49 age bracket.

Think about that: According to Nielsen, a mere 12% of the people who watched the CBS telepic fell within the hallowed demo, while the rating among viewers 50 and up (a 12.2) was nearly 10 times as high.

Those results represent an exaggerated case of an increasingly common trend. Earlier this year, the website Tvbythenumbers listed an assortment of shows where 70% or more of the program’s total audience falls outside the 18-49 demo, including “Dancing With the Stars,” “Blue Bloods” and “NCIS.”

From a sales standpoint, that means networks — despite doing well with those particular shows — are still throwing away more than two-thirds of the chicken.

There’s an irony here: Young adults — the ones networks continue to scramble to attract — are feeling neglected in the political and financial spheres, just as those over 55 are lobbying to gain a greater foothold in terms of their media relevance.

On the one hand, AARP enlisted the suddenly ubiquitous Betty White for an ad campaign designed to “get rid of obsolete stereotypes about aging.”

On the other, an advocacy group called Our Time, representing people under 30, launched a petition drive in response to a CNN poll that didn’t include results for those under 35. (It turned out the number of people reached in that age group was deemed statistically insignificant via the random survey.)

Here’s a hint: Get a mortgage and start consistently voting in greater numbers. Eventually, the right people will pay attention.

In fact, one reason young adults weren’t reached is because fewer of them have land lines. That technological shift, along with growing TV viewership via alternate screens, explains why this cohort is so elusive, and also so prized by advertisers.

Even so, networks and media buyers are exploring new methods to enhance available ratings data, in ways that could eventually re-jigger some aspects of the current media equation.

In March, CBS research guru David Poltrack gave a speech citing the goal of moving from demographic targets toward selling commercial time based on a more nuanced view, cross-referencing set-top box and online-panel data with actual purchasing habits.

“Age and gender has always been a surrogate for trying to get to a potential buyer for a product. It has never been ideal,” said Jane Clarke, managing director of the Coalition for Innovative Media Measurement (CIMM), whose group — financed by an assortment of media companies — has undertaken the daunting task of trying to improve multiscreen audience measurement.

It will be a long time, surely, before the senior-skewing “Blue Bloods” can hold its own, viewer for viewer, against the youth-oriented “Jersey Shore.” But it will be interesting to see which movement makes headway first: Young adults in achieving the political clout denied them, or blunting the media indignities heaped on their parents and grandparents.

In the meantime, stay healthy, kids. Because when it comes to the Medicare system, if not the TV ecosystem, seniors might get the last laugh.