The four candidates for Mexico’s presidency have officially launched their campaigns for the July 1 election, all of them promising change.

Enrique Pena Nieto of the centre-left Institutional Revolutionary Party (PRI), Josefina Vasquez Mota of the ruling centre-right National Action Party (PAN), centre-left coalition candidate Andres Manuel Lopez Obrador and environmentalist Gabriel Quadri are competing to succeed the outgoing incumbent Felipe Calderon.

Pena Nieto, whose PRI governed Mexico from 1929 to 2000, used the word “change” 26 times in his first official campaign speech on Friday.

“Mexico is clear on what it wants, and it doesn’t want more of the same,” Pena Nieto declared in the western city of Guadalajara. “It wants to exit this stage of shadow and darkness and enter a new stage of light and hope.”

Pena Nieto’s focus on “a grand crusade for change” and “the change we want” echoed the 2008 campaign slogan of US President Barack Obama, “change we can believe in.”

The Obama campaign’s skillful use of social media in 2008, when it employed email, text messages and the Web to reach voters, appears to have also made an impact on the Mexican political scene.

Josefina Vazquez Mota, whose pre-campaign appearances have been plagued by logistical difficulties and poor planning, told supporters on Friday to use social media, “this new world that accompanies us,” to attract potential voters.

“It’s going to be hard to reach every corner of the country,” Vazquez Mota acknowledged. In fact, the first female candidate for a major Mexican party has had trouble making it on time to campaign events in Mexico City, let alone the often violent and isolated outlying regions of the country.

Though she is an incumbent-party candidate, Vazquez Mota is campaigning on the one-word slogan, “Different,” perhaps an attempt to distance herself from Calderon’s six-year offensive against drug cartels, during which time 47,000 lives have been lost to drug-related violence.

The clashes between drug cartels and security forces have sapped support for Calderon and his party, which has also failed to reduce the number of poor and create enough jobs for a growing population.

Andres Manuel Lopez Obrador, who is making his second run for the presidency for the leftist Democratic Revolution Party after narrowly losing the 2006 election, said at his first campaign news conference on Friday that he represented “true change.”

Lopez Obrador led weeks of street blockades to protest what he claimed was fraud in the 2006 elections and later anointed himself as “legitimate president.”

He has since been seeking to soften his image, promising a government of “honesty, justice and love”.

“I pledge my heart for the people of Mexico,” he said in a baseball stadium packed with thousands of supporters.