By Steve Holland
WASHINGTON (Reuters) - Republican Jeb Bush offered his most direct assault on Donald Trump to date on Tuesday, retaliating for a series of personal insults with a review of his front-running rival's past record of supporting Democratic causes.
In a Web video, the Bush campaign used Trump's own words in support of Democrat Hillary Clinton and for a universal healthcare system, higher taxes and partial-birth abortion to make the case that he is not a conservative.
Asked by a TV interviewer whether he was a Republican or a Democrat, Trump is seen on the video saying: "You'd be shocked if I said that in many cases I probably identify more as a Democrat."
Bush, 62, is among the Republican presidential candidates whose standing has been damaged by Trump's summer rise. An average of recent polls by Real Clear Politics puts Bush in third place with 9.5 percent, behind Trump at 26.5 percent and retired neurosurgeon Ben Carson at 12 percent.
The video and other comments by the former Florida governor suggest that Bush is willing to take on Trump in a way other Republicans have thus far avoided, raising the possibility of fireworks at the next Republican debate on Sept. 16 in California.
The Bush video came the day after the Trump organization issued a Web video that attacked Bush's belief that immigration is an "act of love" by showing mug shots of three illegal immigrants either convicted or suspected of murder.
Asked by reporters in Miami on Tuesday about the Trump attack, Bush said he considered much of the criticism from his rival to be personal in nature.
The Bush video shows Trump praising Clinton, the former secretary of state and favorite for the Democratic presidential nomination in 2016, as a good negotiator on Iran at a time when Republicans are denouncing the Obama administration's proposed nuclear deal with the country.
"If you look at the record of what (Trump) believes, he supports Democrats," Bush told reporters in Miami. " .... This is not a guy who is a conservative.
"And using his own words is not a mischaracterization. It came out of his own mouth."
(Reporting by Steve Holland; Editing by Lisa Von Ahn)