Republican U.S. senators join push to block Trump's Canadian tariffs

Open this photo in gallery: Senator Susan Collins speaks to reporters outside of the Senate Chambers at the U.S. Capitol on March 13, in Washington, DC.Anna Moneymaker/Getty Images A growing bipartisan cohort of U.S. senators is poised to challenge the White House's justification for imposing tariffs on Canadian goods, in what could be the most significant Republican rebuke to U.S. President Donald Trump of his administration's second term. Senators are expected to cast their votes Tuesday on a resolution in the Republican-controlled chamber seeking to terminate the national emergency the White House declared over illicit fentanyl flowing from Canada into…