Since returning from Las Vegas, both he and his supporters have repeated the message that the Democrats are soft on antisemitism and hostile to Israel.
Vice President Mike Pence’s recent claim that the president is “the greatest friend of the Jewish people ever to sit in the Oval Office” is certainly an audacious one: Mr Trump’s 2016 elecion campaign faced multiple accusations of trading in antisemitic tropes and his failure to condemn neo-Nazi marchers in Charlottesville in the early months of his presidency provoked fury among Jewish groups.
Last November, around three-quarters of American Jews voted Democrat in the midterm elections.
That is not to say that this is a politically flawed strategy. Facing a tight battle for re-election next year, the president is aware that touting his pro-Israel policies to peel away even a small number of Jewish voters might make a critical difference in key swing states such as Florida, Nevada and Pennsylvania.
Perhaps more importantly, Mr Trump is exploiting genuine tensions in the Democratic party.
Moderate and Jewish Democrats have repeatedly attempted to bat away accusations of antisemitism and House Speaker Nancy Pelosi suggested last week that there was “no taint” of Jew-hate in the party.
But Mr Trump’s escalating attacks on Ms Omar — he recently shared a Tweet suggesting she had belittled the events of 9/11 which, the congresswoman claimed, had led to death threats against her — has the party’s leadership in a quandary.
They want to defend Ms Omar from the president’s apparent stoking of anti-Muslim sentiment. At the same time, they don’t want to associate the party with the whiff of antisemitism which now accompanies her.
Thus even Senator Bernie Sanders, the left’s standard-bearer in the battle for the Democrat presidential nomination who had previously sought to diffuse attacks on Ms Omar, last week conceded that she has “got to do a better job in speaking to the Jewish community”.
Mr Sanders’ own increasingly hostile rhetoric towards Israel — which has included releasing videos calling Gaza an “open air prison”, fierce attacks on Benjamin Netanyahu and floating cuts to US military aid to the Jewish state — has appeared to set the tone of the Democrat primary contest.
Like Mr Sanders, rivals such as Senator Elizabeth Warren and former Representative Beto O’Rourke — who labelled Mr Netanyahu a “racist” earlier this month — are keenly aware that polls show support for Israel among liberal grassroots activists is falling fast.
But some Democrats appear keen to buck this trend.
Rising star Pete Buttigieg — the 37-year-old openly gay mayor whose support has leapt in the polls over the past month — may have condemned Mr Netanyahu’s talk of annexing West Bank settlements but he continues to stick to an avowedly pro-Israel line.
After returning from a trip to the country last year, he blamed Hamas for the plight of Gaza, highlighted divisions in the Palestinian leadership and suggested Israelis’ unwillingness to let security threats “dominate your consciousness” was a model for Americans.
Questioned recently about Ms Omar’s attempt to equate alleged human rights abuses by Israel with Iran, Mr Buttigieg bluntly responded: “People like me get strung up in Iran so the idea that what’s going on is equivalent is just wrong.”
When “Mayor Pete”, as his supporters dub him, formally launched his campaign this month, he was interrupted by pro-Palestinian activists critical of his pro-Israel stance.
While other Democratic presidential contenders snubbed invites to address Aipac’s annual conference last month, Mr Buttigieg wasn’t invited — a faux pas, in retrospect, by the normally politically astute Israel lobby group.
California Senator Kamala Harris, with whom Mr Buttigieg is currently jousting for third place in the primary polls, also appears to be sticking with her solidly pro-Israel voting record.
She’s refused activists’ demands to sever her links to Aipac, attacked the BDS movement and condemned any notion of cuts to US aid to Israel.
Her criticisms of Mr Netanyahu, while clear, have lacked the inflammatory tone of some of her Democratic rivals and the senator has not demurred from her belief that Israel has a right to defend itself from Hamas rocket attacks.
As Ms Harris’ campaign communications director told one newspaper: “Her support for Israel is central to who she is.” The senator is married to a Jewish lawyer.
Mr Trump’s effort to paint Democrats as anti-Israel would no doubt be blunted if he finds himself up against Mr Buttigieg, Ms Harris or — if he chooses to run — former Vice President Joe Biden next November.
He might also struggle to maintain the line that the Democrats are antisemitic were they to pick Mr Sanders. Moreover, for all his pro-Israel rhetoric, the president continues to make revealing slips in front of Jewish audiences.
When he last appeared before the RJC in 2015, he famously declared its members would not support him because “I don’t want your money”.
Despite a warmer reception this month, he repeatedly employed the very tropes that he has condemned Ms Omar for, calling Mr Netanyahu “your prime minister” and saying the Democrats would leave “Israel out there all by yourselves”.
Jewish Democrats swiftly asked whether the president would have said “your Taoiseach” to an Irish-American gathering.
For now, Mr Pence’s vaunted claims of Mr Trump’s affinity for them may continue to ring hollow for many American Jews.
