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For the first time in a generation, a Democrat is running for president without facing sustained attacks on his national security credentials. That’s partly due to recession politics, but also because President Obama is pursuing several aggressive counterterrorism policies that leave little room for conservatives to cast him as soft on defense.

The military prison at Guantanamo Bay is still open. Military commissions are trying detainees instead of the federal courts. Drone killings of suspected militants abroad — including American citizens — occur at a much higher rate than under George W. Bush.

Related: Obama’s anti-terrorism record

Many White House watchers say these policies reflect the inevitable tug of actually serving as commander-in-chief: Obama, like other presidents, has embraced executive power once in office after previously criticizing its use.

But there is another critical dynamic shaping Obama’s approach to terrorism, often below the radar.  On key questions of how the U.S. should detain or try terror suspects, Congress has drastically narrowed the administration’s options.

In 2010, Congress unilaterally banned the transfer of Guantanamo detainees into the U.S. To this day, that legislative action prevents the administration from bringing detainees here — even for prosecution in a death penalty trial.

Turning Guantanamo into Hotel California makes it harder for the administration to handle new detainees. White House officials say it also limits their ability to gain cooperation on extradition from other countries.

These kind of blanket rules have fed arguments that Congress has solidified some of Obama’s most aggressive policies — and curbed his ability to reform programs initiated by Bush.

“Congress has made it impossible for Obama to close Guantanamo,” says Larry Korb, a former assistant secretary of defense under Ronald Reagan.  “They made it very difficult for him to try people in civilian court.  That has really made it very tough for him to do the things that he would like to do.”

“After a while, Obama decided it’s not worth it to keep fighting” Congress,” added Korb, who now studies how both branches of government craft security policy at the Center for American Progress.

Reflecting on the Obama administration’s current detention policy, Tommy Vietor, spokesman for the National Security Council, told the Grio, “It is a fact that Congress has put up as many roadblocks as possible to keep the Guantanamo Bay prison open.”

But the controversy, and frustration with the administration from some human rights groups on terrorism issues, extends beyond Guantanamo Bay.

The largest quantifiable gap between Bush and Obama’s counterterrorism approach can be boiled down to a single piece of military data: one. That is the total number of terror suspects that the Obama administration has captured, off the conventional battlefield, and taken into American custody.

Bush, by contrast, detained over 750 individuals at Guantanamo alone. Ultimately, about 600 of them were released without charges, according to Human Rights Watch, reflecting the difficulty of sorting out the high-value targets from lower-level bystanders.

The low capture number under Obama does not mean suspected terrorists are getting a pass.  It means they are getting killed.