US Democratic presidential candidate Hillary Clinton's chief political strategist Mark Penn quit yesterday after news that he lobbied for a free trade treaty with Colombia that Ms Clinton opposes.
Mark Penn speaks to reporters earlier this year in New Hampshire.
A meeting between Mr Penn and Colombia's US ambassador over the trade deal posed political problems for the campaign of the New York senator, who is vying with Illinois Senator Barack Obama to become the Democratic nominee in the November election.
"After the events of the last few days, Mark Penn has asked to give up his role as chief strategist of the Clinton campaign," the campaign manager Maggie Williams said in a statement.
Anxiety about free trade is widespread among the working-class voters Ms Clinton and Mr Obama are courting and both candidates oppose the deal with Colombia.
Mr Penn apologized for the March 31th meeting with the Colombian envoy, which he said was held in his separate role as chief executive of Burson-Marsteller Worldwide, a lobbying firm hired by Colombia to promote a US trade deal with the South American country.
John McCain, who has already won enough votes to secure the Republican nomination, took a break from campaigning but outlined plans to pursue voters often ignored by his party, which had focused on getting conservatives to the polls.
"We need to go all over America ... (and) compete hard in every section of the country," Mr McCain said on "Fox News Sunday" in an interview.
Although he still has not won over many conservatives, Mr McCain made clear he planned a broader campaign than those run by President George W. Bush when he faces either Mr Obama or Ms Clinton as the Democratic candidate in the November election.