Washington (CNN) Three months after Democrats took control of the House -- and with it new powers to investigate and even subpoena all manner of information about President Donald Trump -- a strategy of stonewalling has become the norm as Trump's lawyers work to protect the material he has long kept secret.

This week alone, Trump's private attorneys made clear to government agencies and an accounting firm they should not comply with Democrats' requests for information about the President's finances . And the White House counsel told Congress it will not turn over information related to Trump's involvement in the merger of AT&T and Time Warner

That's on top of a White House denial sent last month for information related to Trump's conversations with Russian President Vladimir Putin. It presages ongoing rejections of requests related to how the White House doled out individual security clearances to senior Trump aides.

Perhaps looming largest: whether the administration will comply with a request from the House Judiciary Committee for a full, unredacted version of the report by special counsel Robert Mueller . A redacted version of the report is expected to be released on Thursday , causing some anxiety among current and former Trump aides over about what embarrassing information might be revealed.

In total, nine Trump administration officials have declined to appear before House committees, according to a Democratic aide. That includes Treasury Secretary Steven Mnuchin, who refused in January to appear before the House Ways and Means Committee to discuss impacts of the government shutdown; and Health and Human Services Secretary Alex Azar, who declined to testify on the administration's separation of immigrant families.

The Democratic aide also counted 35 occasions when the administration either refused to respond or slow-walked committee document requests.

The resistance strategy has angered Democrats, who insist the administration is obliged to comply with their requests.

"We believe that the administration has a constitutional and legal obligation to turn over all of this material," said Rep. Jamie Raskin, a Maryland Democrat who sits on the judiciary and oversight committees. "This is in pursuit of Congress' oversight and legislative functions. In order to function and in order to pass legislation, we need to get information from the government. And so we don't think the administration has the right to be keeping any of this information from us."

White House officials believe there is little downside to stonewalling congressional investigators, even if that results in prolonged legal battles with uncertain outcomes. Blatant defiance from the Trump administration on all fronts could spur years of litigation in the courts, battles that could be drawn out far beyond the lifespan of the Trump presidency and lead to the investigations being minimized if not forgotten.

A person who has been involved with litigations enforcing congressional subpoenas told CNN that when it comes to stonewalling, both political parties have been guilty.

"Administrations in both parties ... are always interested in further discussion, further negotiations and further delay. Time is on their side," the person said. "Regardless of political party, they are always willing to sit down and talk because they could talk forever."

In recent history, showdowns for information between the executive branch and Congress are rare but messy. In a 24-hour news cycle where stories live and die by the minute, extended legal battles could be lost in the shuffle.

The pursuit of documents related, for example, to the Obama-era gun-walking scandal known as Fast and Furious is still ongoing, even though the House Oversight Committee sued for the documents in August 2012 and a judge ruled in January 2016 the Justice Department had to release thousands of pages of information.

Trump himself has told confidants he thinks the flurry of subpoenas will only help him politically, allowing him to paint Democrats as out of control in their bid to take him down. He has already castigated the various investigations on Twitter and at campaign rallies, and believes it is a winning issue akin to his denigration of the special counsel's investigation.

In Trump's mind, according to people who have spoken to him, Democrats have been seeking out his taxes for years without success and the issue has not caused him political damage among his base of conservative voters. While he has conceded Democrats are newly powerful in their attempts to procure the documents, he's expressed confidence in his own legal authority to deny his tax returns to lawmakers.

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At worst, Trump has said, the battles are likely to extend beyond the two years remaining in this session of Congress, believing the 2020 election could provide a reset that renders the investigative requests moot.

"If the President asserts executive privilege, a legal battle could be very long," said Mark Rozell, a professor of public policy at George Mason University and the author of "Executive Privilege: Presidential Power, Secrecy and Accountability."

"Usually these matters are settled short of a legal battle through a process of accommodation between the White House and Congress," Rozell said. "But in this case, it is highly possible that the two branches will end up on a collision course, each side refusing to give an inch. That is where a legal battle may be necessary, though a regrettable circumstance whenever the political branches cannot settle a dispute short of going to court."

The handling of congressional requests and an expected increase in subpoenas is already consuming resources and time inside the White House. That was an expected outcome of November's midterm elections, which saw Democrats assume the majority of the House of Representatives.

Trump's White House counsel Pat Cipollone has overseen a hiring spree of new lawyers to handle the requests after the counsel's office saw its ranks dwindle in the first years of the Trump administration. The White House last week announced five new additions to the counsel's office. Nearly 20 new lawyers were brought on at the start of the year as Democrats began formulating their investigative plans.

Trump's private team of lawyers has also contended with requests from Congress for information related to the President's personal finances. The most recent example came Monday, when Trump's personal attorney wrote the US Treasury to say the agency should turn down a formal request from Congress for Trump's tax returns.

For many staffers working on the high-profile efforts, the threat of court battles is fully baked into their preparations. For months, aides to House Ways and Means Committee Chairman Richard Neal consulted with the House counsel and experts on the best way to go about making a request for Trump's personal and business tax returns. Pressured by liberals to move more quickly, Neal was instead deliberative, saying publicly that he wouldn't rush a process that was likely to end up in the courts.

"We wanted to make sure that the case we constructed was one that stood up under the critical scrutiny of the courts," Neal said.

But Democrats could also be forced to make tough choices. They've sought documents on everything from the President's finances, his immigration policies, questions about whether he obstructed justice or whether his campaign was influenced by foreign governments. In some cases, committee chairmen have gone as far as to issue subpoenas for some of the information, as they did this week in their search for financial documents related to the President.

But even then, enforcing subpoenas could require further legal action, time and money that could distract from the Democrats' other priorities including policy and holding the House of Representatives in the 2020 election.