U.S. President Donald Trump is questioning why his predecessor, former President Barack Obama, and his administration didn't block Russia from meddling in last year's presidential election.
In a Twitter comment Thursday, Trump posed a question: "By the way, if Russia was working so hard on the 2016 Election, it all took place during the Obama Admin. Why didn't they stop them?"
In another remark, Trump noted that Jeh Johnson, Obama's Homeland Security chief, "is latest top intelligence official to state there was no grand scheme between Trump & Russia."
Johnson told a House Intelligence Committee hearing Wednesday that he has no knowledge whether Trump or his campaign aides illegally colluded with Russian interests to help him win a four-year presidential term, an allegation being investigated by Special Counsel Robert Mueller, a former director of the Federal Bureau of Investigation.
Russia's computer-hacking operation leading up to the election led to the release by the file-sharing group WikiLeaks of thousands of emails captured from the files of Democratic party chairman John Podesta, who was the campaign chairman for Trump's challenger, former U.S. Secretary of State Hillary Clinton. The emails embarrassed Clinton in the weeks before the November election, showing behind-the-scenes efforts by Democratic officials to help her win the party's presidential nomination.
Clinton has blamed the disclosure of the emails on a daily basis as one reason for her election loss to Trump, although Johnson said he had no idea about their importance in analyzing the outcome.
Johnson testified his agency was rebuffed by Democratic officials when they offered to help thwart the Russian intrusion into their computer files.
That led Trump to ask in two more Twitter comments, "Why did Democratic National Committee turn down the DHS offer to protect against hacks (long prior to election). It's all a big Dem HOAX! Why did the DNC REFUSE to turn over its Server to the FBI, and still hasn't? It's all a big Dem scam and excuse for losing the election!"
In January, Trump acknowledged that he believes Russian operatives hacked into files at the Democratic party headquarters and said Russian President Vladimir Putin "shouldn't have done it."
For months since then, however, Trump has been dismissive of several probes into Russian interference in the election, calling them a "witch hunt" and saying they are an excuse by Democrats to explain Clinton's defeat. White House spokesman Sean Spicer declined to answer a question this week about whether Trump believes that Russia meddled in the election.
U.S. officials told lawmakers Wednesday there is no question that Russia engaged in widespread interference in last year's presidential election aimed at helping Trump win the White House, but they said there is no evidence that Moscow was able to change the vote count.
Johnson said at a House Intelligence Committee hearing that the extent of Russian hacking into computer files at the Democratic party headquarters in Washington and attempts to infiltrate state election records went significantly beyond past Russian efforts to influence U.S. elections.
"In 2016, the Russian government, at the direction of Vladimir Putin himself, orchestrated cyberattacks on our nation for the purpose of influencing our election — plain and simple," Johnson said, warning that the cyberattacks against U.S. elections would worsen in the years ahead.
WATCH: US Official says Russians Targeted 21 State Election Systems
Putin has rejected Russian government involvement in the U.S. cyberattacks. He has said, however, that "patriotic" hackers might have carried out the attacks on the U.S. election. “I can imagine that some do it deliberately, staging a chain of attacks in such a way as to cast Russia as the origin of such an attack,” the Russian leader said last month.
At a separate hearing, a current Homeland Security official, Jeanette Manfra, told the Senate Intelligence Committee that the agency has evidence that Russia targeted election-related systems in 21 of the 50 U.S. states. Johnson said 36 states accepted help from the federal government in trying to blunt the Russian efforts, even as many states rejected federal oversight of their state-run election operations.