The U.S. power grid, the lifeblood of the nation, is vulnerable to a terrorist attack that could upend life in the country for a dangerously long time, according to a top senator who on Wednesday plans to press the administration on how it plans to secure it.

According to Wisconsin Sen. Ron Johnson, chairman of the Senate Homeland Security and Governmental Affairs Committee, the grid and U.S. communications are at risk, a conclusion he's reached over several months of hearings on U.S. infrastructure and security.

In an opening statement for today's hearing with the FBI, Homeland Security and National Counterterrorism Center, he cited the biggest threats to the U.S. that his committee is hoping to protect.

"Through hearings over the course of the last three years, we have made great strides in identifying problems, finding areas of agreement, and exploring root causes of America's security challenges," said Johnson.

"Through 22 hearings related to border security, for example, we have learned that our borders are not secure and America's insatiable demand for drugs is a root cause of that insecurity. We have held 11 hearings on cybersecurity and critical infrastructure protection, exploring how nation-states and other adversaries continue to attack information networks to disrupt business and steal our nation's secrets. And we have learned how critical infrastructure sectors, including our electric grid, remain vulnerable to attack in ways that could disrupt our way of life for extended periods of time," he added.

Terrorism has also been his focus in other hearings.

"Through nine hearings on terrorism and extremism, the Committee has explored the horrors committed worldwide by terrorist groups like ISIS, including the raping and slaughtering of women and children. ISIS, al-Qaeda, and affiliated Salafi Jihadists are using new methods and technology to increase their audience and inspire terrorist attacks. The U.S. military and intelligence community have made significant strides towards destroying ISIS, and we must complete that mission swiftly and fiercely. However, we have learned that even destroying ISIS will not destroy its hateful ideology or end radical Islamist terrorism," said Johnson.

He concluded in his opening statement, provided to Secrets in advance of today's hearing, "All of these threats remind us of the need to remain vigilant, and of the importance of the men and women -- like our witnesses and the patriotic Americans they lead -- who work every day to keep us safe."

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com