Donald Trump's trial starts with fight over whether case can proceed

The Senate begins Donald Trump’s second impeachment trial on Tuesday with a fight over whether the proceeding is constitutional, as a number of conservative lawyers reject the defense team’s claim that a former president can’t be convicted of a crime by Congress.
 
Republican senators have advanced the constitutional question as the main justification for acquittal. Most of them have avoided directly defending Trump’s actions leading up to and on the day his supporters stormed the US Capitol.
 
The Senate will face the issue head on as the first step in the process, with four hours of debate scheduled