"The Secretary of State needs to be our top diplomat, a person who is in conversation with the President in the White House, always be an advocate of diplomacy and engaging our worldwide partners", Cardin said. "You'd want to send someone who the North Koreans knew had the president's ear, and he obviously does".
The divisions over Mr Pompeo reflect the conflicts over Mr Trump and his "America First" foreign policy.
Trump's supporters pointed to the integral role that Pompeo, in his role as Central Intelligence Agency director, has had in advising the president on national security and foreign policy matters, including how to approach the Iran nuclear deal, which is nearing a critical extension deadline of May 12, and promised denuclearization talks with North Korean leader Kim Jong Un, with whom Pompeo met to discuss the terms of the summit expected next month.
Haspel, whose Senate confirmation hearing is next month, also faces a tough confirmation fight. That changed significantly a year ago when Rex Tillerson's nomination was approved on a largely party-line vote of 56-43 that saw just four Democrats cross the line to vote yes.
Another Democrat, Sen. Jeanne Shaheen of New Hampshire, switched from a "yes" vote to a "no" vote last week, supposedly after pressure from abortion activists to oppose Pompeo.
Days later, after Kim also met with South Korean President Moon Jae-in, the North Koreans announced they were suspending their nuclear weapons testing program.
In a briefing Monday afternoon at the White House, Sarah Huckabee Sanders, the White House press secretary, dismissed Democratic opposition as "pointless obstruction to score cheap political points with their base as a willful attempt to undermine American diplomacy". "Dems have an opportunity to put politics aside, acknowledge our national security is too important, and confirm Mike Pompeo".
Mike Pompeo of Kansas now appears to be headed toward confirmation as the new secretary of State.
A former U.S. Congressman, Pompeo said he believes life begins at conception.
Senator Chris Coons left the chair of the Foreign Relations Committee choking back tears this week.
"There's traditionally been a very close partnership between the State Department and the Senate Foreign Relations Committee", Mr Alterman said.
"I am voting "no" for those reasons, and I think people have good reasons to vote "no" for Secretary Pompeo, both on the foreign policy sphere, and in these areas", Schumer added.
Coons said that he still meant to vote against Pompeo's nomination on the Senate floor. "I haven't said anything 'til today", Schumer told reporters when asked about the nomination.
Pompeo did not travel alone - he was part of a six-member US delegation to North Korea.
Late last week, Mr Pompeo was still making the rounds on Capitol Hill, speaking with key senators who still haven't committed, including Mr Warner, Mr Manchin, and Mr Jeff Flake of Arizona, the only Republican on the Foreign Relations Committee who's undecided.