I think this illustrates why it isn't optional, the filibuster absolutely must go.

Senate Democrats' largely symbolic bid to cut off the Trump administration's support for a Supreme Court challenge to Obamacare failed as expected Thursday, but several Republicans facing tough reelections crossed party lines to back the measure.

Sens. Martha McSally of Arizona, Susan Collins of Maine, Cory Gardner of Colorado, Joni Ernst of Iowa and Dan Sullivan of Alaska, who are trying to reassure voters about their defense of insurance protections for preexisting conditions, backed the Democrats' measure. Another Republican, Lisa Murkowski of Alaska, who opposed Obamacare repeal efforts three years ago, also supported the bill.

But the bill fell 51-43, short of the 60 votes needed to advance.