WASHINGTON — Democrats secured enough votes Tuesday to stop efforts to overturn the Iran deal in the Senate.

Four undecided senators announced their support, bringing the number of backers to 42 — enough to sustain a filibuster of a Republican effort to pass a resolution disapproving the agreement.

The latest backers were Sens. Ron Wyden of Oregon, Richard Blumenthal of Connecticut, Gary Peters of Michigan, and Maria Cantwell of Washington. Sen. Charles Schumer (D-NY) is among only four Democrat nays.