The last time the Senate split 50-50, the closest thing to smartphones were Blackberry devices, considered cutting edge on Capitol Hill. And congressional offices still routinely conducted business by fax machines.

Much in Congress has changed since the five-month period during the first half of 2001, when the Senate was split evenly between Democrats and Republicans. But 20 years on, the Senate looks to be back to an even split, with Vice President-elect Kamala Harris set to break ties in favor of Democrats.