Manchin and Sinema have hurt Biden's agenda, but haven't voted against a court nominee

(CNN)Whatever issues Democratic Sens. Joe Manchin and Kyrsten Sinema have caused for President Joe Biden's legislative agenda, their records on Biden's judicial confirmation efforts are a positive signal for the President as he seeks to replace the retiring Justice Stephen Breyer.

Neither Manchin nor Sinema has voted against any of Biden's lower court nominees so far -- including Biden's picks for the federal judiciary who have attracted significant Republican heat.

Manchin and Sinema stuck with the rest of the Democratic caucus when Republicans were united against the confirmation of Jennifer Sung to the 9th US Circuit Court of Appeals -- a confirmation that required the tie-breaking vote of Vice President Kamala Harris to move forward.

Manchin in particular has attracted liberal ire for holding up Biden's Build Back Better spending plan, and both the West Virginia Democrat and Sinema voted against Democrats' efforts to end the use of the 60-vote filibuster on voting rights legislation. But the filibuster isn't in play for Supreme Court votes anymore.

Since Senate GOP leader Mitch McConnell pushed through a change in filibuster rules in 2017 to confirm Neil Gorsuch, it just requires a party-line, simple majority vote to advance a Supreme Court nominee.

In the 50-50 Senate, all Democrats need to do is stay united, with Harris breaking a potential tie in the event no Republicans break ranks.