Republican presidential candidte Sen. John McCain (l) smiles as his Vice Presidential running mate, Alaska Gov. Sarah Palin, pumps her fist at a campaign rally in Dayton, Ohio, 29 Aug 2008

Republican presidential candidate John McCain says he is "very proud" of his choice of Alaska Governor Sarah Palin as his vice presidential running mate, even as disclosures about her and her family lead to questions on how well his campaign checked her background.

On Monday, Palin disclosed that her daughter, Bristol, 17, is pregnant and will marry the baby's father.  On another front, Governor Palin has hired a lawyer in an ethics probe to determine whether she abused her authority by firing Alaska's public safety commissioner. 

The disclosures have fueled talk that Senator McCain's screening team failed to thoroughly check Palin's background before he selected the relatively unknown governor last Friday to be on the Republican ticket.  The McCain campaign says the Arizona lawmaker was aware that Palin's daughter was pregnant and that Palin was the subject of the ethics investigation.

McCain said Tuesday in Pennsylvania that the vetting process was thorough and that he is grateful for the results.  However, some news reports say his campaign has sent a team to Alaska, apparently to look more deeply into Palin's background.

Some political analysts say Senator McCain's decision to include Governor Palin on the Republican ticket has energized the party.  Delegates at the Republican National Convention in Minnesota admire her opposition to abortion, her support of gun ownership rights and the fact that she is a hunter.

Palin is scheduled to address the convention Wednesday night and formally accept the vice presidential nomination at that time.

Some information for this report was provided by AFP, AP and Reuters.