By E EDUARDO CASTILLO and MICHAEL WEISSENSTEIN Associated Press MEXICO CITY (AP) -- Mexican President Felipe Calderon has begun speaking out about the race to replace him, a potentially controversial move in a country where sitting presidents are barred from campaigning. Mexico passed a series of laws intended to prevent government interference in elections after seven decades of autocratic, single-party rule ended in 2000. Not only are presidents barred from campaigning, federal agencies stop releasing most public information during the election season. However, during a candidates' debate Sunday, Calderon tweeted a response to the leftist candidate's proposal to cut the civil service payroll. And on Tuesday the president, who is barred from seeking re-election, declared the race to replace him to be wide open, despite polls showing his party's rival with a wide lead. Most polls show a double-digit advantage for Enrique Pena Nieto, the candidate of the party that was thrown out of the presidency by Calderon's party 12 years ago. That advantage has been slowly narrowing in the face of corruption allegations against members of Pena Nieto's Institutional Revolutionary Party, or PRI. A student-led protest movement that has marched against the return of the PRI has also worn away at Pena Nieto's advantage. "I'm a democrat, and, as a democrat, I believe in the citizens' vote," Calderon told reporters at a Tuesday afternoon press conference. "In this sense, the election still must be decided. This election isn't decided yet. Candidates "In my opinion, any of the current candidates, especially the three leading ones, could win the election." Most pollsters disagree. With three weeks left until the July 1, Pena Nieto's lead appears solid, and the candidate of Calderon's National Action Party has been eclipsed in second place by Andres Manuel Lopez Obrador, a leftist who narrowly lost to Calderon in 2006 in a race that Lopez Obrador declared to be stolen. Bitter feelings remain on both sides, and the president apparently couldn't resist tweeting a swift response to Lopez Obrador during Sunday night's second presidential debate. After Lopez Obrador said that cutting the salary of high-ranking civil servants could save 300 billion pesos ($21.5 billion), Calderon tweeted that firing every single high-ranking official would save only 2 billion pesos ($143 million). Calderon leaves office in December and has appeared to be deeply concerned about his legacy in recent months, publicly defending his war against drug cartels, and touting Mexico's role as host of a papal visit and the upcoming G-20 global leaders' summit. Lopez Obrador, who was widely criticized for his aggressive response to his 2006 loss, said he respected the president's opinion and wouldn't make a campaign issue out of it. Calderon offered a tepid defense of his debate twittering when asked about it Tuesday, saying "I don't intervene in the debates, I'm not a candidate, I don't appear on television, and I didn't get response time. His tweet, he said, "doesn't indicate any point of view, for or against anyone. This is public information about a topic that is, obviously, of public interest."