The polls didn’t change much from before to after the speech. He got a very small bump while the speech buzz was at a maximum.
Remember, Netanyahu “losing” the election doesn’t mean what it does here, and doesn’t mean he won’t be PM. And, unlike here, voting for minor parties is NOT “wasting” your vote; those parties can negotiate to their own advantage and be part of the government.
Some voters are concerned about the PM’s confrontational relationship with the U.S.President. The speech put that on display. He should have come back triumphant.