The recent unanswered letters include: a request from senators asking for details on Jared Kushner's conflicts of interest; another asking how agencies will implement Trump-ordered changes to Obamacare; and a third asking for details on officials the administration has quietly installed in so-called beachhead teams across the government.
A recent, informal audit by Rep. John Sarbanes, D-Md., found 100 letters that went unanswered as of mid-March, though not all of them made clear requests for information. "These findings confirm what many feared: The Trump Administration has little regard for transparent government," Sarbanes said in a statement.
A Sarbanes spokesman said the audit found just a small handful of letters that did receive responses, such as one sent to the Federal Railroad Administration and another related to a pipeline issue.
The reasons for the lack of responses aren't clear.
It could be another symptom of the president not filling top jobs across the government.
Trump, for example, hasn't nominated anyone for 12 out of the 13 Senate-confirmable leadership spots at congressional affairs offices throughout the government, according to a Washington Post jobs tracker. The Department of Education and the Department of Defense, for example, both have open spots.
Those offices handle congressional requests ranging from minor constituent issues to politically charged demands for documents.
The White House didn't respond to a request for comment.
Other jobs have also gone unfulfilled below the Senate-confirmed level. At the Department of Labor, for example, the office of congressional affairs' website previously listed around 15 politically appointed staffers. It now lists none.
The agency didn't respond to a request for comment.
The lack of responses also shows a hard truth for Democrats: As the minority in both the House and the Senate, they have no clear authority to compel the Trump administration to answer questions or release documents. "No ranking minority members or individual members can start official committee investigations, hold hearings, [or] issue subpoenas," notes a guide to investigations by Morton Rosenberg, a veteran staffer of the Congressional Research Service.
It's difficult to compare Trump's record to that of the Obama administration since there's no hard data on responsiveness to congressional requests. But Republicans say Obama was also less than responsive to their requests.
"It usually took months of persistence to get responses. Sometimes a response never came, and even when it did, the Obama Administration rarely fully answered the questions," said Jill Gerber, a spokeswoman for Sen. Charles Grassley, R-Iowa.
While practices vary agency to agency, there has always been a pecking order in whose letters get quick responses, with subpoena-wielding committee chairs at the top and members of the president's party typically getting preference.
Yet at least some Obama-era congressional affairs offices had policies of responding to letters from any member of Congress.
At the Labor Department, for example, there was a policy of providing a response to all letters from the Hill, regardless of the party of who was asking, according to a former agency official who handled congressional affairs. But response times could take months, depending on the nature of the letter and whether, for example, a response needed to be approved by another agency.
The General Services Administration, which handles procurement for the government, also had a policy of answering all correspondence from the Hill, regardless of the party or the member it came from, according to a former agency official. The policy was to respond within 25 business days.