11 US warships pass through the Suez...

how large is the jewish vote/lobby in the US?

The jewish vote is less than 3% but its concentrated in several key states which given the electoral system increases its impact for its size. On record the vote has always gone massively to the Democrats apart from when there was a 3 way split in Hardings election victory as about 40% of the jewish vote went to the jailed social democrat candidate that year.
As for the lobby, don't you mean the Isreal lobby?