MEXICO CITY - The front-runner in Mexico's presidential race on Thursday said U.S. President Donald Trump's move to send national guard troops to the border was a political ploy based on misinformation to gain support from his conservative base.Leftist Andres Manuel Lopez Obrador, who holds a double-digit lead in polls ahead of a July 1 vote, blasted Trump's plan to post National Guard troops along the Mexican frontier."He's using all this campaign against Mexico as propaganda, that is the only way I can explain that he's trying to send military forces to the border," Lopez Obrador said during a campaign speech in the northern border city of Nuevo Laredo."Because there is no reason to do so," he added. "This great threat on the southern border of the United States that he says is there, does not exist."Lopez Obrador said crime rates in U.S. border cities had been falling in recent years, as had the number of Mexicans seeking to cross the border."This anti-Mexican policy has worked politically because unfortunately there are conservative sectors in the United States with little information and he knows how to awaken an anti-Mexican sentiment, what's called xenophobia, which can be like racism, hatred of foreigners," Lopez Obrador said.Trump's series of comments this week directed at Mexico have thrust the countries' relationship into the center of the presidential campaign, where the ruling party is trailing.Mexico's Senate on Wednesday called on its government to end cooperation with the United States on migration and security over Trump's plans to deploy the National Guard along their shared border.Ricardo Anaya, the second placed candidate who heads a right-left coalition, backed the Senate motion in a media conference early on Thursday."You cannot negotiate or cooperate with threats," he said. "We must make it clear to President Trump that Mexico and the United States can continue to have a profitable relationship, of mutual benefit, or move into a confrontational relationship, where we all lose," Anaya said.