You couldn't be more wrong. If you want to have an honest discussion you can't just make up extreme statements and present them as facts. Just a few off the top issues that come to mind where their positions are diametrically opposed include: Keystone pipeline, killing babies that survive abortions, eliminating coal mining, Marxist supreme court justices, and killing Obamacre.
That you believe Romney is "diametrically opposed" in principle to all those items you mention, is pure wishful thinking and willful self-deceit. Anyone -- anyone -- looking at Romney's record not knowing his political party affiliation, would identify him as a Democrat. There are no "extreme statements" at work in Romney's record nor his recent statments/actions on global warming and the gay agenda. Romney says many things -- but he consistently does only one: ADVANCE THE LIBERAL AGENDA.