| Year and cause | Senator | Party-State |
| 2000 - Deceased | |
| 2000 - Defeated | |
| 2000 - Retired | |
| 2000 - Defeated | |
| 2000 - Defeated | |
| 2000 - Defeated | |
| 2000 - Retired | |
| 2000 - Retired | |
| 2000 - Retired | |
| 2000 - Retired | |
| 2000 - Defeated | |
| 2000 - Defeated | |
| 2002 - Defeated | |
| 2002 - Defeated | |
| 2002 - Deceased | |
| 2002 - Defeated | |
| 2002 - Defeated in primary | |
| 2002 - Withdrew from race | |
| 2002 - Retired | |
| 2002 - Retired | |
| 2002 - Retired | |
| 2002 - Retired | |
| 2002 - Resigned | |
| 2003 - Retired | |
| 2004 - Retired | |
| 2004 - Retired | |
| 2004 - Retired | |
| | Year and cause | Senator | Party-State |
| 2004 - Retired | |
| 2004 - Retired | |
| 2004 - Retired | |
| 2004 - Retired | |
| 2004 - Retired | |
| 2004 - Defeated | |
| 2005 - Resigned | |
| 2006 - Retired | |
| 2006 - Retired | |
| 2006 - Defeated | |
| 2006 - Defeated | |
| 2006 - Defeated | |
| 2006 - Defeated | |
| 2006 - Defeated | |
| 2006 - Retired | |
| 2006 - Retired | |
| 2006 - Defeated | |
| 2007 - Deceased | |
| 2007 - Resigned | |
| 2008 - Defeated | |
| 2008 - Retired | |
| 2008 - Retired | |
| 2008 - Defeated | |
| 2008 - Retired | |
| 2008 - Defeated | |
| 2008 - Retired | |
| 2008 - Defeated | |
| | Year and cause | Senator | Party-State |
| 2008 - Defeated | |
| 2008 - Retired | |
| 2009 - Resigned | |
| 2009 - Resigned | |
| 2009 - Resigned | |
| 2009 - Resigned | |
| 2009 - Resigned | |
| 2009 - Deceased | |
| 2010 - Resigned | |
| 2010 - Deceased | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Retired | |
| 2010 - Lost Primary | |
| 2010 - Lost Nomination | |
| 2010 - Defeated | |
| 2010 - Defeated | |
|