Google has rapidly expanded its lobbying operation, making it one of the top political forces in corporate America. Reuters/Christian Hartmann

Google built its empire through its unrivaled search engine. Now it's trying to preserve that power through an unrivaled political engine. With an average of one meeting per week with White House officials throughout Obama's tenure, the Wall Street Journal reported, Google has evolved into one of the most powerful corporate forces in Washington.

Google's political muscle came to the fore in 2012, when the Federal Trade Commission announced an antitrust inquiry into the tech giant's search business. In response, Google hired a dozen lobbyists and arranged a fusillade of favorable public events and high-level meetings with FTC and White House officials.

The FTC eventually dropped the investigation and Google adjusted its policies on its own. (Incidentally, the FTC's investigation was made public last week.)

Today, only Comcast spends more on lobbying than Google, which spent $16.8 billion in 2014 trying to influence lawmakers. Google was also the second-highest contributor to President Obama's re-election campaign in 2012, falling short only to Microsoft.

When it opened nine years ago, Google's Washington office housed just one person. Now it occupies 55,000 square feet -- which, as the Washington Post noted last year, makes it about the size of the White House. Google has around 100 lobbyists from 20 lobbying firms.

Lobbying isn't the only way Google wields its growing influence. The company supports 145 trade associations and third-party groups, ranging from the Human Rights Campaign to the American Legislative Exchange Council, which drafts model legislation along conservative principles. High-level Google employees have wound up serving in a number of capacities on Capitol Hill, from White House advisory panels to executive branch positions.

The company has defended its wide-ranging political efforts, telling the Journal in part, "We think it is important to have a strong voice in the debate and help policymakers understand our business and the work we do to keep the Internet open."