If Americans choose her as their next president, Hillary Clinton plans to spend some $275 billion to modernize the country's bridges, airports, water systems, broadband Internet availability and public transit and rail services, the Democratic presidential front-runner announced on Sunday.

As she announced her plan at a rally at Boston's historic Faneuil Hall, the former secretary of state said the massive investment was needed to improve the crumbling American infrastructure and in turn keep the United States up to speed in a global marketplace. Clinton called it "a down payment on our future," Bloomberg reported.

"Investing in infrastructure makes our economy more productive and competitive across the board," the former New York senator said. "To build a strong economy for our future, we must start by building strong infrastructure today."

Meanwhile, Clinton painted a grim picture of the current state of the local infrastructure, which has recently received a grade of D+ from the American Society of Civil Engineers (ASCE), the liberal publication Think Progress reported.

"I don't have to tell you what a sorry state we're in," Clinton said.

"Our roads and bridges are potholed and crumbling. Families endure blackouts because our electric grid fails in extreme weather. Beneath our cities, our pipeline infrastructure -- our water, our sewer, you name it -- is up to a century or more old. Our airports are a mess. Our ports need improvement. Our rail systems do as well."

But even though her plan's $275 billion figure quickly grabbed headlines on Sunday, the sum may actually not be enough to make a significant impact, The Atlantic reported. That is because what experts refer to as the U.S. "infrastructure deficit" has run up to a $1.6 trillion, according to a widely cited ASCE study.

"Secretary Clinton is exactly right to call her plan a 'down payment,'" said Damon Silvers, the director of public policy for the American Federation of Labor and Congress of Industrial Organizations. "The reality of our infrastructure deficit is in the trillions, not billions."