Filibuster is a 'guardrail' for democracy -Sen. Sinema

The Arizona Democrat said she has been a longtime supporter of the filibuster, a Senate rule which requires 60 votes in the 100-person chamber to pass most legislation.

Her speech Thursday greatly complicates President Joe Biden's plan to pass voting rights legislation meant to halt Republicans' nation-wide effort to make it harder to vote.

Biden on Tuesday made a full-throated appeal for U.S. voting rights legislation stalled in Congress, saying Democratic lawmakers should rewrite Senate rules to overcome Republican opposition.