WASHINGTON— Immigration reform may be a controversial subject, but conservative Republicans in Congress are attempting to control how the Library of Congress labels that subject and the terms used to describe illegal immigrants.

Conservative Republicans are responding to a move by the library to drop the term “illegal alien” in favor of “noncitizens” or “unauthorized immigration” for cataloging and search purposes. The move came in response to a petition from the American Library Association to change immigration-related search terms to make them less judgmental.

The library’s move, announced in a three-page statement last month, was met with outrage from conservatives, who asked that a provision to block it be added to legislation that funds the legislative branch and its agencies, which include the Library of Congress.

“This needless policy change by the Library of Congress embodies so much of what taxpayers find enraging about Washington,” said Republican Rep. Diane Black in a statement introducing similar legislation. “By trading common-sense language for sanitized political-speak, they are caving to the whims of left-wing special interests and attempting to mask the grave threat that illegal immigration poses to our economy, our national security, and our sovereignty.”

The library makes cataloging changes 3,000-4,000 times a year, says Rep. Debbie Wasserman Schultz, the top Democrat on the legislative funding panel. She says the move inserts a “poison pill” into a normally nonpartisan annual funding bill.

“The Library is in the business of language and nomenclature and should be free to make these decisions outside of the political spectrum,” said Wasserman Schultz. She likened it to dropping archaic words like “negro” and “oriental.”

“What is so controversial about asking the library to use references that are found in the United States Code?” countered Republican Rep. Tom Graves, who inserted the provision into the spending bill this week.

In fact, the library said in a March 26 statement that “the phrase illegal aliens has taken on a pejorative tone in recent years” and added that “aliens” can be confusing since it can also mean beings from another planet.

The bill funding the operations of Congress is the most obscure and little-watched of the 12 annual appropriations bills, making news only because it contains a freeze on lawmakers’ pay and permits sledding on the Capitol grounds. But the legislative branch measure is closely watched by congressional leaders and is one of a handful of the bills that’s usually guaranteed to enjoy bipartisan support. Injecting politics into it is frowned upon.

The immigration issue is but one of many policy topics that are added to the annual spending bills. As the appropriations work gets under way, the Senate is in the unusual position of taking the lead. The appropriations process, once a dominant feature of Congress’ annual schedule, has withered in recent years, with Congress resorting to rolling the traditionally separate measures into a single giant, must-pass spending negotiated in secret at year’s end, rather than through open debate and amendment over many months.

Senate Majority Leader Mitch McConnell has made reviving the appropriations process a priority. The first few bills to make it through the Senate pipeline have been mostly free of what Democrats call “poison pill riders,” despite opportunities to try to block environmental regulations or President Barack Obama’s mostly symbolic executive order on gun violence.

ANDREW TAYLOR, Associated Press