No, this is a twisting of the facts.
It's true that there was a period in 2011-13 when Clinton's State Department debated whether Boko Haram should be classified as a direct threat to the US, while the government fighting Boko Haram in Nigeria warned that doing so would aid their fundraising and status. They chose not to until 2013, but, in 2012 under Clinton and with Clinton's approval, they did classify Boko Haram's leaders as international terrorists.
The Justice Dept and others did advise around this time that Boko Haram could be considered a threat to the US. This isn't the same as recommending that it should be done and doesn't amount to contradicting the State Department's judgement as to what was the best strategic move. The policy was led by State Department regional experts and there's no evidence Clinton was applying political pressure in either direction.
This was all years before Boko Haram were an Islamic State affiliate, while they were almost exclusively active in Northern Nigeria. They were classified as a "Foreign Terrorist Organization" that does constitute a threat to the US in 2013, which was also the first year their reach expanded to neighbouring countries (Niger and Chad).
There are lots of fact-checks into this and related claims, the most thorough seems to be this from the Washington Post from 2014 about a closely related claim.
In detail
To be classified a foreign terrorist organization (FTO) by the US state department:
Three key criteria must be met:
- It must be a foreign organization.
- The organization must engage in terrorist activity or terrorism...
- ...[which] must threaten the security of U.S. nationals or the national security (national defense, foreign relations or the economic interests) of the United States
Obivously, Boko Haram met the first two criteria since they were founded in 2009. The first suggestion that Boko Haram might meet this third criteria (specific threat to the US) appears to be a House Homeland Security Committee report in 2011, but this isn't definite on the matter:
Based on Boko Haram’s evolution and recent public warnings by the U.S. State Department to U.S. citizens in Nigeria, Boko Haram may meet the legal criteria for State Department FTO designation. Such designations are subject to a rigorous statutory process and through investigation, which the State Department needs to initiate.
This, and the "Boko Haram Terrorist Designation Act of 2012", are the main thrust of the "efforts of Members of Congress who were trying to make the designation" discussed in the question, but even they didn't outright call for Boko Haram to be immediately designated, they simply called for the State Department to consider doing so, and explain its decision. That act of congress called for:
(A) a detailed report on whether... [Boko Haram] ...meets the criteria for designation as a foreign terrorist organization...
(B) [if not] ...a detailed justification as to which criteria have not been met
...and it did get passed into law in an altered form in 2012, as an amendment to another bill.
A version of the bill became an amendment to the National Defense Authorization Act, passed in December 2012, requiring the secretaries of state and defense to produce a classified report on the strategy for countering Boko Haram
The case against classifying Boko Haram as an FTO came primarily not from the state department, who "vigorously debated" it, but from the people responsible for actually fighting Boko Haram: the Nigerian government. From Nigerian Ambassador Adebowale Adefuye:
“Our government is working hard to defeat the motley band of criminals popularly known as Boko Haram... Recognition through FTO designation by a sovereign the size and stature of the United States would give Boko Haram the title they seek and status they desire, stimulating a fundraising effort that has not yet been attainable from their current perch in northern Nigeria.”
This was confirmed as being a factor in the State Department's policy:
“The debate was really about the Nigerian attitude toward designation,” Robert P. Jackson, principal deputy assistant secretary of state for African affairs, told Congress. “The government of Nigeria feared that designating these individuals and the organizations would bring them more attention, more publicity and be counterproductive.
The State Department under Clinton did actually go further towards designating Boko Haram as an FTO than the Nigerians wanted. In 2012, under Clinton, Boko Haram's three leaders were designated international terrorists. This policy was devised (as is normal for such things) as a recommendation by appropriate regional staff, diplomats, regional experts, etc:
The strategy, which represented a compromise in the positions of Benjamin and Carson, was set in discussions with Deputy Secretary William J. Burns, who is a career Foreign Service officer. The administration would name three leaders of Boko Haram as specially designated global terrorists while holding out the possibly of a broader designation of the entire group as a means of improving the behavior of Nigerian forces battling Boko Haram.
The article goes on to discuss how this compromise approach gave the US diplomatic leverage over the Nigerian government, which was important given concerns that the Nigerian army were using the fight against Boko Haram as a cover for politically-motivated human rights abuses in a region containing many opposition supporters (something many argued at the time was actually fuelling support for Boko Haram).
In other words, it was a step-by-step diplomatic process. It was made clear that formal designation of the group could come later — and it did, the very next year. But in the meantime, the State Department hoped it could use the threat of designation — and the pressure from Congress — to induce better behavior by the Nigerian military and a more serious approach to the threat by the Nigerian government.
In 2013, Boko Haram expanded to have a presence in neighbouring Chad and Niger, and could no longer be argued by Nigeria to be a domestic matter. Boko Haram were given FTO status that year.
Breaking down the specific claim
As Secretary of State, Hillary Clinton refused to designate Islamic State affiliate Boko Haram in Nigeria, which was named the deadliest terrorist organization in 2015, a terrorist group.
Highly misleading, it misrepresents three things:
- General acknowledgement of terrorism and recognition as "a terrorist group" is conflated with formal designation of FTO status. For a localised regional group (like Boko Haram were at the time), the latter involves potentially flattering them with an official statement that they're a threat to the US or its interests.
- A state department decision agreed by relevant state department officials to do something across a time frame in a certain diplomatic way is misrepresented as a personal refusal by Hillary Clinton to do that thing at all, which also ignores the fact that she approved a major step towards it (designating Boko Haram's leaders).
- Boko Haram are talked about as if their current status ("Islamic State affiliate Boko Haram... deadliest terrorist organization in 2015") applied during the time period in question (2011 and 2012), which is false: at that time they were a brutal but largely localised insurgency with no links to ISIS.
She not only refused, but she hindered the efforts of Members of Congress who were trying to make the designation. The FBI, CIA and Justice Department wanted Boko Haram designated but, ultimately, the State Department opposed the designation despite hard evidence from our Intelligence services.
Also misleading and in some places simply untrue:
- It misrepresents real recommendations that Boko Haram could be so designated as if these departments recommended they should be immediately designated despite warnings from Nigeria that doing so would benefit them.
- It talks as if Hillary Clinton was actively progress towards designation, when actually, the state department did begin the process of moving towards designation, and did go further towards it during Clinton's tenure than the Nigerians wanted.
- It claims the State Department opposed designation, which isn't true: they were in favour of bringing in designation in a measured way which didn't boost Boko Haram or undermine efforts to co-operate with and influence the Nigerians to take "a more serious approach to the threat".