WASHINGTON — Owners of ancient water vessels are likely to be quite pleased with the Senate, which voted overwhelmingly this month to generally exempt them from a fire-retardant materials requirement. But that is about the extent of bipartisan legislation to emerge from Congress during the first 100 days of unified Republican governance.

A divisive election, the growing use of arcane rules that disenfranchise the minority party and a chaotic White House have combined to create one of the least productive opening acts by Congress in recent memory.

In the Senate, legislators have appeared to stop trying. Important cabinet appointments, a Supreme Court confirmation and a vast array of deregulation measures have all been passed without the 60-vote requirement that was once customary. Driven at once by haste and partisanship, Congress has been hampered from moving forward on the tax code, infrastructure and the health care law.

In the House, not even a healthy Republican majority has proved enough. On Thursday, House Republican leaders again failed to round up enough votes among their own members, leaving some in the party politically exposed in the process. A beloved House tax proposal appears to have been jettisoned by the Trump administration before it could even get going.