Newly empowered House Democrats kicked off a barrage of investigations into President Donald Trump's taxes, real estate business and Russia ties Thursday, raising the pressure on the White House after two years of insulation by a Republican majority.
Trump lashed out about "presidential harassment" as one House committee opened a hearing into forcing the release of his long-hidden tax returns, and another began questioning his controversial policy to separate immigrant children from their parents at the US-Mexico border.
"The Dems and their committees are going 'nuts,'" Trump tweeted.
"The Republicans never did this to President Obama, there would be no time left to run government," he said.
Both sides were girding for tough legal clashes pitting congressional powers against those of the presidency.

US President Donald Trump and Russia's President Vladimir Putin shake hands during a meeting on the sidelines of the G20 Summit in Germany, on July 7, 2017. Source: AFP
House Judiciary Chairman Jerrold Nadler threatened Trump's acting attorney general, Matthew Whitaker, with a subpoena if he did not turn over records of his communications with the White House in reference to Special Counsel Robert Mueller's ongoing investigation into Russian election meddling.
And Adam Schiff, the chairman of the House Intelligence Committee, laid out a plan to begin probing Trump's business ties to Russia, citing fears of money laundering and of "foreign financial or other leverage over President Trump."

House Intelligence Committee Chairman Adam Schiff wants to examine Donald Trump's business interests. Source: AAP
Schiff's committee is planning to hear testimony from the president's former personal lawyer, Michael Cohen, who has already divulged to investigators inside information about the operations of the president's real estate business, the Trump Organization and Trump's 2016 election campaign.
"So now Congressman Adam Schiff announces, after having found zero Russian Collusion, that he is going to be looking at every aspect of my life, both financial and personal, even though there is no reason to be doing so. Never happened before!" Trump tweeted.
Probes heighten impeachment threat
After being stifled for two years by majority Republicans, the Democrats won control of the House in November, allowing them to open an investigative assault on the White House in the same way that - contrary to Trump's claim on Thursday - Republicans laid siege to president Barack Obama.
Those probes would add to the legal and political burden facing the president from Mueller's probe into possible collusion between the 2016 Trump campaign and Russia, and a Justice Department investigation in New York into various activities of the campaign and Trump Organization, his umbrella company.
Together, the probes elevate the chance that Trump could face impeachment if serious wrongdoing is found.
Thursday's House Ways and Means hearing into Trump's taxes would break what he declared in 2017 as a red line - that investigations should not touch his business and finances.
Unlike previous presidents, Trump has refused to release his tax records. His lawyers claim they have been under review by the Internal Revenue Service since 2002.
A 2016 New York Times analysis based on limited information concluded that Trump may have paid minimal or even no taxes each year since 1995.
The Chairman of the committee, Representative Richard Neal, has the power to review privately anyone's tax returns, and possibly make them public. But demanding Trump's tax records from the Treasury could lead to a pitched legal battle over presidential prerogatives.
Business ties to Russia
Schiff's Intelligence Committee is also planning a deep-dive into Trump's financial and business ties to Russia, suggesting that they could involve money laundering.
"The president's actions and posture towards Russia during the campaign, transition, and administration have only heightened fears of foreign financial or other leverage over President Trump," Schiff said in a statement Wednesday.
Cohen, who was a senior executive in the Trump Organization, was to be the committee's first witness Friday in a closed session, before he begins a three-year prison sentence for tax evasion and other crimes he said were undertaken at Trump's bidding.
But on Wednesday Schiff announced cryptically that Cohen's testimony would be delayed until February 28 "in the interests of the investigation."
The committee has decided to send transcripts of its closed-door interviews last year with Trump campaign associates to the Mueller investigation, amid suspicions that some may have lied about their Russia ties.
Trump bashed Schiff in a tweet on Thursday.
"So now Congressman Adam Schiff announces, after having found zero Russian Collusion, that he is going to be looking at every aspect of my life, both financial and personal, even though there is no reason to be doing so. Never happened before!" he said.