WASHINGTON - The White House continued Tuesday to defend President Donald Trump's recent Twitter outburst that accused former President Barack Obama of wiretapping Trump Tower while Trump was a presidential candidate last year.
Reporters pressed spokesman Sean Spicer for evidence to back up the president's claim during an on-camera briefing, but Spicer said that would have to be part of the congressional probes into Russia's efforts to meddle in last year's presidential election.
"I think the smartest and most deliberative way to address the situation is to ask the House and Senate intelligence committees, who are already in the process of looking into this, to look into this and other leaks of classified information," Spicer said amid several demands for proof from reporters.
Plenty of denials
Obama has denied Trump's allegation, and so has former Director of National Intelligence James Clapper.
"There was no wiretap against Trump Tower during the campaign conducted by any part of the national intelligence community," Clapper told ABC News.
The continuing swirl of questions about Russia and whether any Trump campaign officials had contacts with Russian officials continues to be a major political distraction for the White House, Republican strategist John Feehery said. "It is a distraction from the legislative work that the president has to do. It is a distraction from trying to get his team in place," he said.
Feehery added that Trump's penchant for issuing his thoughts on Twitter was also an issue of concern for congressional Republicans as they move ahead to try to implement his agenda.
"It's not clear to me whether this is part of a concerted strategy or this is just who he is. It's also not clear if he is going to settle down or if this is the new normal that we all have to acclimate ourselves with," Feehery said.
Trump and some Republicans have demanded an investigation into his claims involving Obama and the alleged wiretapping, but there are plenty of questions about that, George Washington University Law School legal analyst Alan Morrison said.
"The first question is not a legal question, it's a factual question. Is there any basis for it? And so far there has been no evidentiary basis other than suspicion, and suspicion is not enough to start an investigation," Morrison said.
WATCH: Feinstein: 'Special Prosecutor Should Lead' Russia Investigation
Congressional intelligence committees and the FBI have begun probing possible links between the Trump campaign and the Russian government. But Democrats, including Senator Dianne Feinstein of California, favor a broader, independent investigation.
"It's vitally important that the American people have trust in this investigation and that there is not even the appearance of a conflict of interest or political influence," Feinstein said.
It's too early for that, Republican Senator Chuck Grassley of Iowa said. "There are times when special counsels are appropriate, but it is far too soon to tell at this time," he said.
Both senators spoke at a Senate Judiciary Committee hearing Tuesday on the nomination of Rod Rosenstein to be the next deputy attorney general.
If confirmed, Rosenstein could play a key role in the government's probe into Russian meddling, since Attorney General Jeff Sessions recused himself from cases involving the issue last week.
WATCH: Rosenstein Would 'Hire A Special Prosecutor' For Russia Investigation
Democrats at the hearing pressed Rosenstein about whether he was committed to pursuing an inquiry free from politics and conflict of interest. He tried to reassure the committee, saying, "And whether it is a law or a statute or some other mechanism, I would ensure that every investigation is conducted independently."
But it's not just Democrats keeping a close eye on the Russia controversy.
South Carolina Republican Senator Lindsey Graham vowed to be aggressive when he was asked about the issue during a recent town hall meeting in his home state.
"I'm not only going to push for a Russia investigation, I'm going to punish Russia for trying to interfere in our elections," Graham said.
Someone who knows the Russians well is former U.S. Ambassador to Russia Michael McFaul, who served under Obama.
"I am so passionate about the need for a bipartisan, independent commission to investigate that, because that is the only way that we are going to turn leakers into witnesses. And if we don't do that, I don't think we'll ever know that story," McFaul said at George Washington University last week.
Health plan, tax reform
Much of Tuesday's White House briefing was dominated by Health and Human Services Secretary Tom Price's rollout of details on the plan to repeal and replace the Affordable Care Act, also known as Obamacare, something many congressional Republicans would prefer to focus on as well.
Health care legislation and tax reform should keep Republicans busy for the next several weeks, if not months.
And as much as possible, strategist Feehery predicted, lawmakers will do all they can not to be distracted by the president's comments on Twitter.
"It does make Republicans a bit nervous, but it shouldn't come as any surprise. I mean, he did precisely this during the campaign," he added.