The article quotes him as saying:
"Throughout the Muslim communities that I visit, and indeed throughout Europe, there is significant anger and resentment and, yes, perhaps sometimes hatred and indeed sometimes an all-too-growing intimidation and violence directed at Jews generally as a result of the continuing tensions between Israel and the Palestinian territories and other Arab neighbors in the Middle East."This quote doesn't excuse the anger, resentment, and "perhaps sometimes hatred"; it simply describes his perception. Ditto for another quote in the article in which Amb. Gutman appears to be simply describing the cycle of violence in the Middle East. His mistake was to use the charged word "anti-Semitism." (If he had made the same remarks without reference to "two forms of anti-Semitism," the remarks probably would have passed without too much notice.) The article says the ambassador has now issued a statement on his website, regretting that his remarks might have been misconstrued, etc.
In addition to the reactions from Romney and Gingrich, the remarks have prompted other reactions, including (again according to the Wash. Post article) a statement from the Children of Jewish Holocaust Survivors that refers to the "ongoing campaign by the White House to undermine Israel."
The U.S. gives Israel on the order of $3 billion a year, a very large portion of which, I believe, is military/security assistance. Obama administration officials, from Hillary Clinton on down, have said repeatedly that the U.S. is firmly and unwaveringly committed to ensuring that Israel maintains its QME (that's 'qualitative military edge'). Pres. Obama himself has made this clear on more than one occasion. The Obama administration wasted (in retrospect) about a year-and-a-half or so urging Israel to curtail construction of settlements. There was a brief-ish moratorium, after which settlement construction resumed (though perhaps at a slower pace than before). The admin appointed former Sen. George Mitchell its special envoy to the region tasked with bringing the conflict to a resolution, as he had in N. Ireland. Sen. Mitchell butted his head against brick walls for a while and then resigned. As long as the $3 billion per year remains untouchable, which it does because Congress sees to that, nothing the Obama administration says can in any way "undermine" Israel because everyone understands that the administration's words, unlike some words in international politics, are empty. No leverage will be brought to bear in connection with them. Since the Six Day War, Israel has been primus inter pares among U.S. allies. This has been true no matter who is in the White House and no matter what they have said about the Israel-Palestinian conflict. The word "undermining" in the statement quoted seems to mean "ineffectually disagreeing with certain aspects of Israeli government policy while tacitly communicating that such disagreement is indeed ineffectual because it will not be accompanied by any actions of consequence."
There are very good reasons for the U.S. to support Israel. Whether there are good reasons for the U.S. to support Israel in the particular way that it does is a legitimate subject of public debate (although if you try to debate it you will have all kinds of accusations leveled at you; viz. Walt and Mearsheimer). In any case, the charge that the Obama administration has an "ongoing campaign" to "undermine" Israel is, to put it mildly, groundless.