No amount of argument or evidence will persuade those who hold one view to change their minds to the opposite position.
Opponents simply start from different premises, and it is impossible to reconcile the differences.
The debaters simply talk past each other, with no hope of moving their opponents. The impeachment of President Clinton is that kind of issue. Few minds will change as members of the House of Representatives debate articles of impeachment this week, because the two sides aren't talking about the same set of facts. One side believes that the president of the United States committed perjury and obstructed justice in order to cover up evidence that he solicited sexual favors from subordinates in the workplace. The other side believes that the president simply tried to conceal information about a private, consensual relationship that, no matter how tawdry, ought to be no one's business but his own.