Biden aides reveal the president is only 'dependably engaged' for a few hours each day

Joe Biden's aides have revealed that the aging President alternates between being alert and utterly confused - but is 'dependably engaged' for only a few hours each day. 

Biden's performance in Thursday's Presidential debate shocked many in the Democratic party with his rambling answers and apparent disorientation. 

But White House aides told Axios that they were not surprised, and that it was common knowledge within his inner circle that there were seemingly two versions of the president. 

The first version, they said, is confident and focused while the second appears confused, tired and old. 

White House aides told the outlet that Biden is only 'dependably engaged' between the hours of 10am and 4pm each day and outside of these times he is more likely to misspeak or seem lost.

White House aides told Axios that they were not surprised by Biden's performance at the debate, and that it was common knowledge within his inner circle that there were two versions of the President

In Thursday's 90-minute debate, Biden appeared to repeatedly lose his train of thought and struggle to finish sentences.

Afterwards, Biden himself said: 'I don't walk as easily as I used to. I don't speak as smoothly as I used to. I don't debate as well as I used to.'

His performance sparked panic among the Democrats with former key Barack Obama adviser David Axelrod saying there was a 'sense of shock' in the party and there would be 'discussions about whether he (Biden) should continue'.

But some aides told Axios that they were not surprised by his performance and expressed fresh concerns about whether the president is fit for another term. 

They reported that his limitations and mistakes are well known in the White House with many referring to the sense that there are two presidents: one competent, one old and confused. 

They said which Biden you get at any one time depends on a number of factors including the time of day. 

Biden is 'dependably engaged' from 10am to 4pm and so many of his events are held within these hours, they told Axios. 

They told the outlet that Biden is only 'dependably engaged' between the hours of 10am and 4pm each day and outside of these times he is more likely to misspeak or seem lost

Thursday's debate on the other hand, started at 9pm.  

Outside of those hours they said Biden is more likely to become tired and confused or misspeak.

They also said he is worse when traveling abroad and more easily tired.  

In response, White House spokesperson Andrew Bates told Axios that there 'is one Joe Biden'.

He added: '[He] works his heart out fighting for families like the one he grew up in in Scranton, and who, because of his determination, experience and decency, keeps achieving unprecedented results for them.'