Scott Walker tweaks older candidates with Rubio birthday tweet

Washington (CNN)Scott Walker is using Marco Rubio's birthday to offer a not-so-subtle reminder: Most of the rest of the presidential field is much older.

Walker, the 47-year-old Wisconsin governor, tweeted a birthday greeting to Rubio, the Florida senator who turned 44 on Thursday, saying it comes "from one forty-something to another."
Here's who's not a "forty-something": former Florida Gov. Jeb Bush, who's 62; former Arkansas Gov. Mike Huckabee, who's 59; retired neurosurgeon Ben Carson, who's 63; Kentucky Sen. Rand Paul, who's 52; and New Jersey Gov. Chris Christie, who's 52.
And then there's the Democratic frontrunner, Hillary Clinton, who's 67.
    In fact, among declared candidates in either party, Texas Republican Sen. Ted Cruz (44) is the only other forty-something.
    Republican candidates, and particularly Rubio, have made a generational case for themselves, arguing that the 2016 election is time for a departure from the families that have dominated American politics for decades -- a jab at both Clinton and Bush.