One can imagine members of Congress, esp the House, have their ears close to the ground (i.e. pay a lot of attention) as to what their constituents want:
House passes resolution condemning Hamas attacks on Israel
Driving the news: The resolution received overwhelming bipartisan support, passing by a vote of 412-10.
Just nine Democrats voted against the measure: Reps. Rashida Tlaib (Mich.), Cori Bush (Mo.), Jamaal Bowman (N.Y.), André Carson (Ind.), Al Green (Texas), Alexandria Ocasio-Cortez (D-N.Y.), Summer Lee (Pa.), Delia Ramirez (Ill.) and Ilham Omar (Minn.).
Another half dozen Democrats, including Progressive Caucus Chair Pramila Jayapal (Wash.), voted "present," while Rep. Thomas Massie (R-Ky.) voted against the measure.
Note that this is Oct 25th, quite a bit into the air strike campaign.
And while I am not going to expend the energy to confirm all of them, I recognize enough of those to think that most of the No voters are in very safe Democrat districts, where as a comment already noted, progressive voters are going to... what, vote for Trump (who would likely not be an improvement for Palestinians, on past record)???
And, again going by the list of Nays, this would totally be "Oh, Biden is in cahoots with THE RADICAL LEFT!!!" for Republican attack ads.
There are many reasons for America's support for Israel. But the Q's consideration of electoral calculations point precisely in the opposite direction of that cited in its premises:
Electorally, it pays to be for Israel, not against it.