Gregory Korte

USA TODAY

WASHINGTON — President Obama has vetoed just two bills in nearly six years as president – fewer than any president since James Garfield's term was cut short by an assassin in 1881.

He's also issued fewer veto threats than any president since at least Jimmy Carter, according to a USA TODAY analysis of presidential documents.

And even when the Obama White House does issue a veto threat, it's often more nuanced than those of his predecessors. More than 80% of veto threats issued by the Obama administration come not from the president directly but from unnamed "senior advisers," allowing the president room to negotiate.

The president's veto power is likely to take a higher profile in the last two years of his presidency, as he's confronted for the first time by Republican majorities in both chambers of Congress. But when and how often he uses his veto power depends as much on Congress as it does Obama.

Obama avoided a veto showdown Tuesday when the Senate narrowly failed to pass a bill to shortcut the presidential approval process and approve the Keystone XL pipeline. The White House had threatened to veto similar bills in the past, but Obama was remarkably coy about his intentions if it had passed this week.

Republicans say they'll try again next year. "If we pass this bill and President Obama vetoes it, then that is his decision, that is his prerogative, but the responsibility will lie squarely on his desk," said Sen. Pat Roberts, R-Kan.

Indeed, no sooner had the midterm election returns come in than Republicans started daring Obama to veto bills. "We will send the president bill after bill, until he wearies of it," Sen. Rand Paul, R-Ky., said on election night. "And if the president insists on vetoing those bills, then in 2016 the people will rise up and elect a government that will restore those American values."

Vetoes increase when the other party has complete control of Congress. President George W. Bush had no vetoes his first term and only one after six years, to go with 72 veto threats. But once Democrats took control of Congress in 2007, Bush issued 142 more veto threats and made good on 11 of them.

Obama could continue to wield his vetoes sparingly. Congress is passing fewer bills than ever, especially the minor bills that were most often the subject of vetoes in past decades. With the exception of President Gerald Ford, who used vetoes in an attempt to balance the budget, the number of vetoes has generally declined with every president since Franklin Roosevelt. And, most important, Republicans still don't have a filibuster-proof margin in the Senate, meaning Democrats can still block GOP bills from even reaching the president's desk.

That dynamic could fall apart quickly as the 2016 elections approach.

"They're not going to feel disposed to do his dirty work," said Cary Covington, a professor at the University of Iowa. "They'll defend their own interests, but they're not inclined to toe the line for the president."

Obama could even see some vetoes overridden, Covington said. Among Democrats, "There's going to be game of chicken to take a tough vote to protect the president," he said.

READ MY LIPS

Some of the most dramatic presidential veto threats come in high-profile speeches. President Ronald Reagan channeled Clint Eastwood in Sudden Impact when threatening to veto a tax increase in 1985: "Go ahead — make my day," he said.

Campaigning for president in 1988, George H.W. Bush threatened to do the same when he told Congress, "Read my lips: No new taxes."

And President Bill Clinton held up a veto pen in his first State of the Union Address: "If you send me legislation that does not guarantee every American private health insurance that can never be taken away, you will force me to take this pen, veto the legislation, and we'll come right back here and start all over again."

Obama has used his State of the Union speeches to threaten vetoes three times: on spending bills in 2010 and 2011 and this year on an Iranian sanctions bill.

But most veto threats are far more routine — and even bureaucratic. Since the Carter administration, the Office of Management and Budget has weighed in on major legislation through what's known as a statement of administration policy, or SAP.

The Office of Management and Budget does not discuss the internal deliberations leading up to a statement of administration policy, OMB press secretary Emily Cain said.

But a USA TODAY analysis of those statements shows that the Obama White House has used them more infrequently than any president since at least Clinton, the first president for whom all SAPs have been made public.

SAPs can offer support for a bill, express concerns or oppose it. But Obama doesn't threaten to veto every bill he doesn't like. The administration has issued statements opposing 45 bills — 16 of them "strongly opposed" — while stopping short of a veto threat.

Veto threats come in two varieties. In a presidential veto threat, the White House says the president will veto the bill. But most veto threats — especially under Obama — come from unnamed "senior advisers," who recommend a veto to the president.

"By pushing the veto threat farther away from the president, it gives the president more wiggle room," said John Gilmour, a political scientist at the College of William and Mary. A presidential veto threat, on the other hand, means, "You should trust that to mean the president will veto the bill. The president's credibility is at stake."

"Presidents don't issue idle veto threats," he said.

Under Obama, OMB has only issued statements – with or without a veto threat – once a bill has been scheduled for a floor vote or gets a hearing in the House Rules Committee. And unlike his predecessors, Obama's White House has not allowed his Cabinet secretaries to make veto threats.

Obama has personally threatened to veto 18 bills during this Congress. Twelve bills would have repealed all or part of the Affordable Care Act, five were related to last October's government shutdown and one would have frozen pay for federal workers. Another 57 times since 2013, the threat came from senior advisers.

Monday, the White House released three veto threats on Republican environmental bills. All came from senior advisers.

The sponsor of one of those bills, Rep. Steve Scalise, R-La., said the veto threat was "irresponsible and is further proof that he does not want to work with Congress in a bipartisan way to create jobs." The Obama administration said the bill, which would require it to publish a new rule every time it updates air quality standards, would create "unnecessary confusion" about how the standards apply to a new factory.

There are subtle differences in how the Obama administration uses statements of administration policy compared to his predecessor. Bush seemed to go out of his way to make veto threats, sometimes threatening to veto bills carrying certain amendments — even amendments that hadn't been introduced yet.

By contrast, Obama is more likely to suggest he'd sign a bill he likes than he is to threaten to veto a bill he doesn't.

Bush also used veto threats in conjunction with a controversial practice known as the signing statement. In 2005, Bush threatened to veto any bill carrying the so-called McCain amendment, which would ban torture of prisoners in U.S. custody. But after Congress passed the bill over his threat, Bush signed the bill anyway – but with a signing statement maintaining the McCain amendment was unconstitutional and therefore unenforceable.

Obama also used a signing statement, rather than a veto, to nullify a provision in a defense bill that required him to notify Congress 30 days before releasing suspected terrorists from the U.S. prison at Guantanamo Bay. Obama said that provision " violates constitutional separation of powers," and three months later released prisoners in exchange for Army Sgt. Bowe Bergdahl.

VETO BAIT

Obama's two vetoes both came in his first term, on bills passed overwhelmingly by a Democratic Congress. And both came without warning.

The first came on a 2009 stopgap spending bill that, Obama said, became redundant when Congress passed a full-year spending bill the same day. The second veto came on a relatively minor bill that consumer advocates tried to scuttle at the last minute because it could have helped speed up foreclosures.

Those "surprise vetoes" come when the president vetoes a bill without issuing a threat. But in the next two years, Obama's vetoes are more likely to be on "message bills" — bills the Republican Congress knows the president will veto. And that's the whole point.

Political scientists call these bills "veto bait."

"In the theoretical models in political science, vetoes shouldn't happen. If both sides were purely interested in policy making, they would come to a compromise point," said Matthew Jarvis of California State University, Fullerton. "When you see a veto, your nose should be sniffing for politics. It takes two to tango, and then the question becomes, why do they want to tango?"

There could be two reasons: First, congressional Republicans may want to force the president to publicly take an unpopular position. But it also might be the opening gambit in a negotiation.

Sen. Mitch McConnell, R-Ky., who will lead the Senate Republicans in the next Congress, has said he intends to force the president to make tough calls on vetoes. "Presidents do have the right to veto – something the president hasn't had to do," McConnell said after the election. "The first two years he loved everything he got and the last four years the current majority made sure he never got anything he didn't like. So, that's how you cure gridlock."

In addition to the Keystone bill, Republican leaders say they'll try to pass bills repealing the Affordable Care Act and – perhaps more likely to pass – repealing the medical device tax that helps pay for it.

House Speaker John Boehner already has a list of bills he wants Obama to either sign or veto. "Let's take the 46 jobs bills that are sitting in the United States Senate that have been held up by the Democrat majority in the Senate," Boehner said after the election. "Almost all of those passed the House on a bipartisan basis. And I believe that almost all of them enjoy bipartisan support in the United States Senate."

Obama has already said he supports three of those bills, including a patent overhaul measure.

But there are veto threats on 25 of those bills — not including two others the administration opposes and three others it has "concerns" about.

Follow @gregorykorte on Twitter.