They are the two major front-runners for the 2016 Democratic presidential nomination, but the ages of Vice President Joe Biden and Hillary Clinton are more and more being viewed as hurdles to winning the White House.

And now Larry Sabato, the head of the University of Virginia's Center for Politics, has dubbed them the "Geritol generation." Worse, he reveals that his younger staff laughs at the "fossils."

On Election Day 2016, Clinton will be 69, Biden 73.

The oldest candidate to win the White House, former President Ronald Reagan, was 69 on his Election Day and he had to fight questions about his age. Unlike during Reagan's campaigns, when age questions focused on his ability to handle the job, the current concerns about Biden and Clinton are more generational with younger voters expressing an interest in a younger candidate.

By comparison, most of the GOP front-runners are baby boomers.

But with no other Democrat close to Clinton and Biden in the polls, it appears for now that the two will be the choices during the primaries.

Last week, Sabato's Crystal Ball team issued their new presidential ranking and it had Clinton in the first tier, Biden in the second tier. Some questioned Biden's placement and polls show strong Democratic support for Biden.

The questions prompted Sabato to revise and extend his remarks, as they say in Congress, with a note about the ages of the front-runners:

"Don't underestimate Joe Biden — Biden has more loyalists than you'd think, and quite a few true believers about a third presidential bid. Sure, Biden was an asterisk in the 1988 and 2008 cycles, when he ran for the White House the first two times. But he's gotten a big job promotion since, with a jumbo jet and dozens of staffers, and the same indefatigable spirit. President Obama isn't going to diss Biden by endorsing Hillary if they both run, so Obama's troops may be more divided in '16 than they look now. The Geritol generation may be well represented at the next Iowa caucus, with Biden at 73 and Hillary at 68. The young Crystal Ball staffers laugh at the 'fossils,' but they give the senior guy at the Ball some hope that it isn't all downhill after 65."

The Republicans certainly expect Biden and Clinton to dominate the race. On Friday Republican National Committee even released a video focused on Biden and his potential candidacy in a bid to suggest that both potential candidates are running for a third Obama term.

Paul Bedard, The Washington Examiner's "Washington Secrets" columnist, can be contacted at