Elizabeth MacDonough has been the nonpartisan Senate Parliamentarian for the past 13 years since 2012.
She has a high level of respect and regard by most members of the Senate, and has been seen as the “guardian” of Senate rules, who does what is best for the Senate and its reputation. This is true even when some disgraceful Senators, like presently Alabama Senator Tommy Tuberville, have called for her to be fired for refusing to back all of the demands of Donald Trump.
She has presided over periods of Democratic and of Republican party majorities, and been part of the institutional history of the upper chamber in a very distinguished manner.
MacDonough has enforced the so called “Byrd Rule”, named after the late Senator Robert Byrd of West Virginia, which allows elimination of “extraneous” proposals that interfere with reconciliation of provisions of legislation, with 60 votes needed to overrule the Senate Parliamentarian, a high barrier.
It seems likely that Senate Majority Leader John Thune of South Dakota will not listen to a few Senators who want her fired, as she is well respected, and Thune is reluctant to interfere with her nonpartisan approach to Senate rules.
Already, with North Carolina Senator Thom Tillis and Kentucky Senator Rand Paul, opposed to aspects of the House bill, it is possible that the Trump “Big And Beautiful” bill might fail to get past the Senate, if on final passage, other Senators, such as Lisa Murkowski of Alaska, Susan Collins of Maine, and Josh Hawley of Missouri, vote to reject the legislation as it is constituted right now, particularly regarding Medicaid cuts.