By Yasmeen Abutaleb

(Reuters) - As the U.S. presidential campaign heats up, Facebook Inc is going out of its way to show its neutrality - an increasingly urgent matter for the social network as evidence of its power continues to emerge.

Recent studies have shown the site has extraordinary influence. According to research scheduled to be published in August in the Journal of Communication, when people tagged their friends on Facebook in voting reminders, turnout increased by 15 to 24 percent.

During U.S. presidential primary elections this year, a Facebook reminder that informed people when their state’s voter registration deadline was approaching and provided a link helped produce a surge of nearly 650,000 new voter registrations in California alone, according to Secretary of State Alex Padilla.

In the United Kingdom, a Facebook reminder days before the deadline to register to vote on whether the country should exit the European Un