TAMPA -- U.S. Sen. John McCain estimates that if proposed defense spending cuts go into effect Jan. 1, the state of Florida will lose about 42,000 jobs and about $3.6 billion.

McCain predicts massive defense sector unemployment and gaunt armed forces at a time when the country needs a strong military.

“We are looking at, in our view, an emergency situation,” McCain, R-Ariz., said Monday to a crowd of about 60 supporters in Tampa.

McCain and fellow senators Kelly Ayotte, R-N.H., and Lindsey Graham, R-S.C., came to town on Monday as part of a four-state tour to protest what McCain calls “draconian cuts” to the nation’s defense budget. The senators also will hold sessions in Virginia, New Hampshire and North Carolina — states that are all home to military bases and defense contracting jobs.

Republicans and Democrats agreed to automatic defense cuts — along with automatic cuts to a host of other programs — last year as part of a stop-gap measure if Congress failed to reach consensus on a way to reduce government spending.

If the automatic cuts occur, about $1 trillion will be trimmed from the defense budget over 10 years, McCain said, and the size and scope of the military would be reduced dramatically.

Florida, a major swing state in November’s presidential election, has more than 20 military bases. Tampa alone is home to thousands of military personnel and their families, and its own MacDill Air Force Base is touted as one of the bay area’s largest economic engines.

Although the proposed cuts do not name MacDill specifically, that didn’t stop the visiting politicians from issuing dire warnings.

“MacDill Air Force Base is toast if this goes through,” Graham said.

Mayor Bob Buckhorn, a Democratic, also protested the cuts at the meeting.

“MacDill Air Force Base is so critically important to us and this community that what we are talking about today could have a devastating effect,” he said. “This is important, this is personal.”

McCain said that as President of the United States, Barack Obama is also the commander-in-chief of the armed forces, and security should be his first priority.

“I hope that by our travels ... we arouse enough public opinion to force the President of the United States and Congress to sit down and find a resolution,” he said.

Gene Jones, president of the local chapter of Veterans for Common Sense, said the prospect of reduced spending is not the problem. But reckless spending in the defense sector is.

The defense budget is “bloated” to begin with, and the defense department isn’t held accountable for the money it spends. Often, Jones said, the Defense Department is given money for items it doesn’t want.

Others have made the same argument.

A report from Taxpayers for Common Sense, a non-partisan watchdog group in Washington, D.C., said the government could save about $700 billion over the next 10 years by cutting back on unnecessary weapons, reining in “out-of-control” service contracts and reducing investments in excess nuclear weapons.