"All right, should I do this?" Harris could be heard asking as her fingers reached for the small ivory gavel in front of her. With a nod from the Senate parliamentarian, Elizabeth MacDonough, Harris gave the gavel a short tap and performed the most visible role afforded to her under the Constitution.

"On this vote, the yeas are 50, the nays are 50," Harris intoned. "The Senate being equally divided, the vice president votes in the affirmative, and the concurrent resolution as amended is adopted." Scattered applause greeted her announcement.

Harris' predecessor, Mike Pence, wound up casting 13 tiebreaking votes, a record for modern vice presidents. It's a job he, Harris and every other vice president past gained in almost an accident of history, an afterthought role for an afterthought position. As the vice presidency was debated in the closing days of the Constitutional Convention, Roger Sherman of Connecticut worried that the officeholder "would be without employment" if the senatorial duties weren't tacked on.

It's not a gig that Harris apparently relishes at the moment, though. The Los Angeles Times reported in January that her advisers would prefer that Senate Democrats find ways to avoid her having to cast tiebreaking votes all that often. They are, in fact, "hoping the Senate duties don't distract from her other responsibilities and priorities too much, hindering travel, dominating her schedule or interfering with her ability to become an active player in the Biden White House."

But aside from her tiebreaking vote giving Democrats the majority, Harris is poised to be essential to one of the most pressing issues the Senate will confront this Congress: ending the filibuster. Senate Democrats have been considering getting rid of the arcane quirk of the rules, which stands in the way of the caucus' agenda. The marathon of voting last week was the price for avoiding the 60-vote threshold to cut off debate on legislation that the filibuster otherwise imposes. If and when the time comes to nuke the filibuster, Harris would — and should — become the latest in a string of vice presidents to try to chip away at the filibuster's power.

Her aides' reported hesitancy to dwell too much on the Senate isn't surprising given what the vice presidency has become. But in America's early days, there was little of the hand-in-hand cooperation between the president and his running mate that we see in modern administrations. While Thomas Jefferson and Alexander Hamilton locked horns in George Washington's Cabinet, John Adams was mostly confined to the legislative branch, sitting in on the first meetings of the newly formed Senate.

As presiding officer, Adams was to help guide the flow of traffic on the Senate floor, recognizing speakers and ruling on points of order and other procedural matters. "It is not for me to interrupt your deliberations by any general observations on the state of the nation, or by recommending, or proposing any particular measures," Adams said when first addressing the Senate in April 1789.

But Adams didn't stick to that promise for long. During one infamous early debate, he suggested that Washington hold the title of "His Highness, the President of the United States of America, and Protector of the Rights of the Same." The suggestion was roundly rejected. After a year of Adams' lectures to the Senate, he got a warning from a friend that he was making a lot of enemies with his interference. Adams in response said he had "no desire ever to open my mouth again upon any question." This time he kept his word.