Doug Stanglin, and Nicole Gaudiano

USA TODAY

WASHINGTON — President Trump’s explosive and unsubstantiated claim Saturday that then-President Obama wiretapped his phones before the November election broke new ground in terms of a president publicly assailing a predecessor and left observers and lawmakers seeking a more expansive explanation than Trump's string of tweets.

“In the past, presidents have privately muttered accusations against their predecessors,” said Jack Pitney Jr., a former aide to House and Senate Republicans and a political science professor at Claremont McKenna College. “It’s very unusual for a president to come this close to accusing a predecessor of a potential crime.”

Trump offered no evidence to support his accusations, lobbed during a Saturday morning tweetstorm. An Obama spokesman rejected them as “simply false.”

The outburst follows several days of stories raising questions about meetings between members of the Trump campaign and Russian officials, particularly two previously undisclosed meetings between now Attorney General Jeff Sessions and Russian ambassador Sergei Kislyak.

"How low has President Obama gone to tapp [sic] my phones during the very sacred election process," Trump wrote. "This is Nixon/Watergate. Bad (or sick) guy!"

Kevin Lewis, Obama's spokesman, said in a statement: "A cardinal rule of the Obama Administration was that no White House official ever interfered with any independent investigation led by the Department of Justice.

"As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen," he said. "Any suggestion otherwise is simply false."

American law enforcement and intelligence agencies were known to have been examining intercepted communications and financial transactions as part of a broad investigation into possible links between Russian officials and Trump associates, The New York Times reported in January. The investigation was being led by the FBI, aided by the National Security Agency, the CIA and the Treasury Department’s financial crimes unit, the Times said.

Electronic surveillance under such an investigation would require a warrant approved by a FISA court judge. Presidents do not have the authority to order such wiretaps and would not as a routine matter even be aware of them.

If the president were involved in the process, it would be "scandalous and unheard of," said Ron Hosko, a former assistant FBI director. Hosko called the allegations "unprecedented“ and "unlikely to have occurred in the very broad way” that Trump described.

“The notion that you get a call from the president who says start intercepting calls on this phone ... is frankly ridiculous,” he said. “It doesn't work like that. There’s no magic wand in the hand of Barack Obama to order the FBI to go flip a switch and start collecting on a political opponent.”

Ben Rhodes, Obama's foreign policy adviser, responded to Trump in a series of tweets, first stating that "No President can order a wiretap. Those restrictions were put in place to protect citizens from people like you."

If Trump were privy to information that his phone was indeed wiretapped, it would suggest that a FISA court had found probable cause to issue such a warrant.

Sen. Chris Coons, D-Del., told MSBNC this week that he believes the FBI is in possession of transcripts that might detail communication between top Trump campaign members and Russian officials. The transcripts, which Coons said he has not seen, could reveal if the Kremlin and Trump’s team colluded to influence the 2016 election.

The wiretapping story will have “legs” because it can only go in one of three directions, “all of which are bad,” Pitney said. If the tapping was unauthorized, someone broke the law. If it was authorized, there’s a paper trail and a court found cause for the wiretap. And if there wasn’t a wiretap, Trump invented the story, he said.

“Whatever way it goes, it’s not good,” Pitney said.

Sen. Lindsey Graham, R-S.C., said during a Clemson town hall meeting Saturday morning that it would be the biggest political scandal since Watergate if it’s true that Obama either wiretapped Trump’s phones, illegally — or was able to obtain a warrant to lawfully monitor Trump’s campaign activity with foreign governments. Either scenario is worrisome, he said.

“It’s my job as a United States senator to get to the bottom of this,” he said to applause. “I promise you I will.”

Sen. Bene Sasse, R-Neb., said citizens deserve more information about such serious allegations. If Trump's phones were legally tapped, he said, Trump should ask that the application for surveillance be made available to the public or “at a bare minimum,” to the Senate.

"We are in the midst of a civilization-warping crisis of public trust, and the President’s allegations today demand the thorough and dispassionate attention of serious patriots," he said in a statement. "A quest for the full truth, rather than knee-jerk partisanship, must be our guide if we are going to rebuild civic trust and health."

The tweet blasts began at 6:26 a.m. from the Winter White House at Mar-a-Lago in Florida when Trump raised the Sessions issue by noting the first meeting between the senator from Alabama and the Russian ambassador was set up by the Obama administration as part of an education program.

Eight minutes later, he raised the charge of illegal surveillance by the Obama administration: "Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!"

Then: "Is it legal for a sitting President to be 'wire tapping' a race for president prior to an election? Turned down by court earlier. A NEW LOW!"

And: "I'd bet a good lawyer could make a great case out of the fact that President Obama was tapping my phones in October, just prior to Election!"

To that, Rhodes responded: "No. They couldn't. Only a liar could do that."

Rep. Adam Schiff of California, the top-ranked Democrat on the House Permanent Select Committee on Intelligence, slammed Trump for offering no evidence to support "this spectacularly reckless allegation."



"No matter how much we hope and pray that this President will grow into one who respects and understands the Constitution, separation of powers, role of a free press, responsibilities as the leader of the free world, or demonstrates even the most basic regard for the truth, we must now accept that President Trump will never become that man," he stated.

House Minority Leader Nancy Pelosi of California accused Trump of trying to deflect from the Russia controversy.

"The Deflector-in-Chief is at it again," she tweeted. "An investigation by an independent commission is the only answer."

Sessions recused himself from any Trump-Russia investigation after the Justice Department acknowledged he spoke twice with the Russian ambassador last year and failed to disclose the contacts during his Senate confirmation process.

Sessions said he had not tried to mislead anyone but could have been more careful in his answers. He planned to file amended testimony Monday, a Justice Department spokesman said.

The president responded to the Sessions issue obliquely Friday by taking a swing at Senate Minority Leader Charles Schumer, noting the New York senator previously met with Russian President Vladimir Putin.

In a tweet, Trump posted a photo of Schumer with Putin during the Russian leader's visit to New York in 2003. He demanded an investigation of "close ties" between Schumer, Pelosi and Russia and "lying about it."

He called Schumer, who has demanded Sessions' resignation, a "total hypocrite."

Trump's Saturday morning tweets come less than a day after radio talk show host Rush Limbaugh accused Obama of executing a "silent coup" to unseat Trump and render him "effectively immaterial" as president, using “the pretext of Russian interference in the election to justify wiretaps."

Also on Friday, the far-right Breitbart News Network reported on steps Obama allegedly took to undermine Trump, including a FISA request to monitor Trump and advisers. Breitbart, previously led by Trump’s chief strategist Steve Bannon, supports its claim by linking to a Heat Street story that relies on anonymous sources, which Trump has said media “shouldn’t be allowed” to use.

"He tends to believe things that he sees on outlets such as Breitbart," Pitney wrote in an email. "Here's the problem: Suppose the next dubious story involves a military threat. Does he then send troops into combat? Does he launch a nuclear strike? One would hope that he'd check with the intelligence community, but he seems to distrust it."