An emphasis on Israel has the potential to turn off other groups of voters, including some Muslims, Catholics and more liberal Protestants, Green said. But he added that past elections have shown that evangelicals and Jewish voters tend to place a much higher priority on issues involving Israel, while "groups on the other side who might be bothered by it tend to have other issue priorities."
"There's not as much of a downside talking about these issues as there is an upside," Green said.
Veteran Republican strategist Charlie Black, who supports Fiorina, said that by now she has probably locked down conservative voters who feel strongly about Israel. But he said the Israel trip could lead to a second look from some Jewish voters as well as donors willing to contribute to both candidates, particularly those who feel President Obama has not been sufficiently supportive of Israel.