Half of voters expect Biden to forget where he is during first debate in Atlanta and walk off the wrong side of the stage - but could those low expectations spell trouble for Trump?

Almost half of likely voters expect President Joe Biden to make a series of embarrassing flubs when he goes to head-to-head with Donald Trump in their first debate this month.

Some 49 percent think he will forget where he is and 41 percent said they expect him to walk off the wrong side of the stage, according to a new poll by J.L. Partners.

Another 40 percent think he will trouble standing up during the CNN debate in Atlanta, Georgia, on June 27.

In contrast, voters expect a domineering performance from his Republican rival, and overwhelming expect him to emerge the winner.

Some 79 percent expect Trump to interrupt Biden and 54 percent think his microphone will be cut off at some point.

J.L. Partners polled 500 likely voters from June 10 to 11 and asked them what they expected to happen when Joe Biden and Donald Trump face off in their first presidential debate

Pollster James Johnson said the numbers were dreadful for Biden.

'They show voters' deep concerns about his ability to govern,' he said. 'However, there may be a medium-term win for Biden in that Trump has clearly set expectations for Biden in the debate very low.

'If Biden gets through and doesn't have a major mishap then that will be a win for the president.

The two candidates are due to face each other on the debate stage later this month and then again in September.

To test the public's expectations, J.L. Partners asked 500 likely voters for their views on June 10 and 11. 

Half said they expected Trump to win, while only 39 percent said they expected Biden to win.

Almost three quarters said they thought Biden, who has battled a stammer for his entre life, would fluff his words at some point.

The results are a reminder of Biden's recent bumbling performances, which have provided plenty of ammunition for the army of Trump meme makers. 

However, both candidates are ageing—Biden is 81 and Trump turns 78 on Friday—have a tendency to speak in meandering sentences that end suddenly or are filled with non-sequiturs.

All groups in the poll said they expected Trump to beat Biden in the first debate in Atlanta

Former President Donald Trump was on Capitol Hill meeting Republicans on Thursday

Meanwhile President Joe Biden was with other world leaders at the G7 in Italy

Trump offered his own, less scientific assessment in a typically freewheeling appearance at the National Rifle Association convention last month. 

And he acknowledged that Biden could benefit from low expectations and a soft media lens. 

'If this horrible individual finishes the debate, which I think he will ... if he's standing, if he's standing, they'll say it was a brilliant performance,' said Trump, before imagining the reviews. 

'It was a brilliant performance. They've never seen anything like it ... very much reminiscent of the days of FDR.'

FDR, he said, had a 'beautiful patrician voice, magnificent voice, great debater.'

The poll also found that 61 percent of voters expect Trump to tell a rambling story.

But in his NRA speech, Trump claimed the circuitous stories were carefully delivered.

'You know there is a genius to what I'm doing,' he said, interrupting a meandering story about President Macron of France, which may or may not have had something to do with tariffs, and included a brief interlude in praise of the name 'Emmanuel' and an attack on CNN. 

'You do know that I go from here to there, and it all comes back into a beautiful picture.

'It's a beautiful thing.'