White House hopeful Hillary Clinton clashed with rival Barack Obama in Wisconsin Monday as she sought to regain momentum in the Democratic nomination race after a string of defeats.
On the Republican side, runaway front-runner John McCain won the endorsement of former president George Bush, a new backer who could help the maverick senator woo conservatives suspicious where his loyalties lie.
A win in Tuesday's Wisconsin primary could give Clinton's faltering campaign a much-needed shot in the arm before a major showdown on March 4 in Ohio and Texas, where a combined 334 delegates are at stake. The Democratic rivals fired off television advertisements and campaigned across the Midwestern state in a tough fight for Wisconsin's 74 delegates with the latest poll showing Obama with a narrow five-point lead over Clinton.