Politicians who overstay their cognitive ability - What's Your Point?

Its a tough 15 seconds to watch - 81-year-old Senate Minority Leader Mitch McConnell clearly struggling.

 McConnell's 90-year-old senate colleague Dianne Feinstein had a similar cognitive breakdown just a few weeks ago when an aide was compelled to instruct her to simply "vote aye" after the six-term Democrat launched into a stumbling speech. 

 Bottom line - how old is too old to serve in the United States Congress?

WATCH MORE WHAT'S YOUR POINT?

There's a saying that goes something like this.... "Father Time remains.... Undefeated" 

· Hot mic catches confused Feinstein being told to vote 'aye' in awkward committee moment

· What happened to Mitch McConnell?