PHOTO: New Mexico City airport is under construction. (photo by Greg Custer)Mexico's new international airport in Mexico City is struggling to overcome major delays. According to a report in Bloomberg, the choice to build on swampland isn’t the only hurdle planners face. There are several construction challenges—one being that the land chosen for the airport is sinking at the rate of almost one foot per year—as well as land disputes, legal woes and politics. Construction at the site is delayed as land disputes postponed the installation of a railway that was designed to be used to bring heavy equipment to the site. The railway is now on track to enter service.MORE Destination & TourismRunway three is also delayed, which could push back the scheduled debut of the facility in 2020. Politics could also play into the finishing of the airport. Right now, left-leaning politician Andres Manuel Lopez Obrador, a candidate in next year’s election who is currently leading in the polls, thinks the airport is a waste of money. Obrador believes the scope of the project is a big risk, saying it’s too expensive and proposes scrapping the whole thing. He has suggested building new runways at a military base 30 miles away from the existing airport to resolve the problems of overcrowding and connecting the two facilities. The details and the logistics of that project have not been provided. READ MORE: Mexico is Leading the Hemisphere's Medical Tourism The new airport is one of the foundations of current Mexico president Enrique Pena Nieto's infrastructure plans and something that he promised to deliver. If the airport is delayed significantly, it could pose problems for the 2018 election and Pena Nieto's party’s chances at a win.Additional challenges that could postpone the airport’s 2020 debut include the collapse of an overpass during an earthquake last week as well as a bankruptcy filing by one of the key contractors, says the Mexico News Daily. When completed, the futuristic-looking, environmentally sustainable new airport will be capable of handling up to 68 million passengers per year. Its signature “X”-shaped design is the vision of architect and Pritzker Prize winner Norman Foster and Fernando Romero. The glass-and-metal structure will be able to collect and recycle rainwater and use natural light as much as possible.