Activists are claiming victory after the Obama administration announced it would put off any decision on approving the Keystone XL tar sands oil pipeline until 2013 — well after the 2012 elections. On Thursday, the White House said it needed more time to review the route of the proposed 1,700-mile, $7 billion TransCanada pipeline and its environmental impact on Nebraska’s Sandhills region. The announcement was made just days after more than 10,000 people circled the White House calling on President Obama to reject the project. Opponents had objected to the pipeline over its potential dangers to the areas along its path and its tapping of the carbon-intensive Canadian tar sands oil fields.