It works like this:
History says Jesus was a Jew.
A disgruntled liberal or two dispute that.
The burden of proof is on the new idea.
Therefore the burden of proof is on the disgrunteled liberals.
Of course Jesus was a Jew. His lineage is listed in front of the Synoptics. He preached in Synagogues (let a gentile try that!), he called the temple HIS Father's house, he was tried by the Jews and executed by the Romans at the insistence of the Jews (they were not allowed to execute). Jesus observed the Jewish Passover, was reprimanded by the Jews for working on the Sabbath (did Jews worry about Romans working on the Sabbath?) and amazed the teachers of the law with his knowledge of it when he was only 12!
Now where is the evidence that he was not a Jew?
Not quite accurate. First of all, the Jews did execute....'stoning' and beheading. The Jews had control over 'religious' problems... the Romans had control over 'state' problems. This would indicate that Jesus was seen as more of a STATE problem (declaring himself 'King'). This would be seen as TREASON and its punishment was the most harsh...crucifixion (a gentile death), reserved for offenses against the STATE. The Romans were not concerned if Jews blasphemed as in the alledged case of Jesus declaring himself God.... the Romans called themselves Gods all the time.... nope, the crucifixion wasn't about Jesus declaring himself God, it was because of the 'King' of the Jews statement. He was seen as a threat to the government.
FWIW