President Bush, center, flanked by Vice President Dick Cheney, left, and Attorney General Alberto Gonzales, in the Rose Garden of the White House on Thursday, Nov. 9, 2006. AP Photo/Ron Edmonds

Presidential power is spiraling out of control, making George W. Bush the most powerful American leader since at least WWII, according to a new analysis.

But the current president, now entangled in a controversy over his recent decision to assert Executive Privilege, can’t take full credit for the power grab, the researchers argue. A number of factors have converged over the past 60 years to turn the American presidency into a position of incredible influence that has a negative effect on American politics and which won't change just because someone else takes charge of the White House.

In their new book "Presidential Power: Unchecked and Unbalanced" (W. W. Norton, 2007), Johns Hopkins University political scientists Benjamin Ginsberg and Matthew Crenson trace the history of the presidency since the middle of last century, uncovering a series of murder mystery-like motives, means and opportunities that have shaped the executive branch into the most powerful institution on the globe.

Ginsberg and Crenson are not the only researchers to spot the radical change.

“The presidency has grown in size and in power throughout the 20th century,” agreed Christopher S. Kelley, a political scientist at Miami University in Ohio.

Power grab

In a telephone interview last week, Crenson explained how American politicians today are driven by different desires than they were in the past.

“We have these people with enormously grandiose ambitions, who don’t just want to be president—they want to change history,” Crenson said. Politicians used to be propelled into the presidency by their parties; now they are self-propelled, he said.

This change was accompanied by a general decline in public political participation, said the authors. People’s dwindling interest in politics—and in congressional activities in particular—has allowed presidents to capitalize on unique opportunities.

“When popular participation diminishes, congressional influence goes down, and one of the obstacles for presidential power is significantly reduced,” Crenson said. “You can see over the course of the 20th century, presidents have either grabbed or invented one instrument of power after another.”

For instance, when Warren G. Harding set up the Bureau of the Budget in 1921, he essentially created a mechanism by which the executive branch could oversee the activities of federal agencies, Crenson explained.

And when the public looked to the president for help during the Great Depression, Congress gave Franklin D. Roosevelt the resources to establish the Executive Office of the President, an entity that houses the powerful National Security Council and the Office of Management and Budget, said Kelley, the Miami University researcher.

Watergate effect

According to Kelley, however, by far the biggest instigator last century was Watergate. After the scandal, Congress reacted by constraining presidential power, all the while still expecting the president to lead.

“If any president wanted to be successful, and to bequeath an office stronger than he found it, he would need to develop unique arguments, theories, devices, etcetera, that would enable success,” Kelley told LiveScience. “Hence presidential unilateralism [and] working through the executive branch agencies to accomplish what he couldn't with the Congress.”

Watergate also prompted the Supreme Court to first recognize the power of Executive Privilege, which allows the executive branch to resist certain legislative and judicial interventions. President Bush asserted the privilege last week to keep the White House and several of his former aides from supplying subpoenaed documents to Congress in an investigation related to the replacement of federal prosecutors.

Some speculate that Bush will also evoke the privilege to keep his former aides from testifying and to prevent the White House, Vice President Cheney’s office, and the Justice Department from complying with a separate set of subpoenas related to the administration’s eavesdropping program.

Reigning it in

While many might think the relatively unchecked power in today's White House is largely due to how President Bush operates, the authors, who support different political parties, see the shift as more of an institutional—and constitutional—issue.

“People need to realize that this is not a problem that’s going to be solved by electing somebody other than George W. Bush,” Crenson said. “This is a serious constitutional problem—constitutional in both senses of the word—that is going to take some very careful thought to remedy.”

The best way to for the public to change the balance of power is to support Congress in its efforts to make substantive policy, Crenson said. Since the legislature has two parties, compared to the president’s one, it is likely to make better decisions, he contends.

Kelley agrees. The public needs “to insist that Congress vigorously defends its own prerogatives and holds the executive branch accountable,” he said. “This means that Congress holds oversight hearings, that Congress demands information, and that Congress doesn't delegate.”

In order for this to happen, however, congressional goals need bipartisan support, Kelley said. This is quite difficult today, given that members are often condemned for “reaching across the aisle.”

“The single-minded focus on the next election and to win for the Party at all cost will continue to give the executive branch the advantage,” Kelley said.