He did not directly call for impeachment. He said that under the standards by which Republicans had impeached Clinton, Bush also could be impeached.
Here's what he said at NAACP and apparently again on MSNBC (I have no transcript).
Democratic candidates take stage at NAACP Convention July 15, 2003
...Graham intensified his criticisms, telling reporters before the candidates' forum that Bush's deceptions would land him in more trouble if the Democrats controlled Congress.
''If the standard of impeachment that the Republicans set for Bill Clinton, that a personal, consensual relationship was the basis for impeachment, would not a president who knowingly deceived the American people about something as important as whether to go to war meet the standard of impeachment?'' Graham said.When MSNBC ran the headline that he was calling for impeachment, Graham issued a statement saying they were wrong.
Graham is my man, and I think he's standing up and speaking out wonderfully well, but I don't want people to run with MSNBC's headline that he called for impeachment and then be badly disappointed to discover otherwise.