> Completely sure it not "illegal, and the grounds for exclusion from the Knesset, to disagree with that statement."
“A candidates' list shall not participate in elections to the Knesset, and a person shall not be a candidate for election to the Knesset, if the objects or actions of the list or the actions of the person, expressly or by implication, include one of the following:
“1. negation of the existence of the State of Israel as a Jewish and democratic state;
“2. incitement to racism;
“3. support of armed struggle, by a hostile state or a terrorist organization, against the State of Israel.”
A party with an objective "negating the existence of the State of Israel as a Jewish and democratic state" is not the same as voicing disagreement. Almost half of the Knesset voted against 'Israel as the Nation-State of the Jewish People' basic law, and many regularly voice disagreement with this definition.
When you can arbitrarly define who is part of that democratic state and who is not, it is not democracy. The Palestinans are living under the control of the Jewish state and they have no right to vote.
“A candidates' list shall not participate in elections to the Knesset, and a person shall not be a candidate for election to the Knesset, if the objects or actions of the list or the actions of the person, expressly or by implication, include one of the following:
“1. negation of the existence of the State of Israel as a Jewish and democratic state;
“2. incitement to racism;
“3. support of armed struggle, by a hostile state or a terrorist organization, against the State of Israel.”
https://www.knesset.gov.il/laws/special/eng/basic2_eng.htm