Trump treads carefully as calls swirl for Biden to exit

As the Democratic Party fights over whether Joe Biden should step aside before November's presidential election, rival Donald Trump has declined to join the pile-on.

Biden's halting debate last week against Trump fuelled concerns among voters around the president's age and ability to govern -- fears that Republicans have often been eager to highlight.

Yet the Trump campaign has now pushed back against the idea of Biden, 81, stepping down.

Democrats dumping their own candidate...