Mitt Romney will begin raising money jointly with the Republican National Committee, as the GOP front-runner's campaign moves its focus from a protracted primary fight to the general election.The arrangement between the RNC and Romney camp would allow donors to contribute as much as $75,000 per person, according to The Wall Street Journal, which first reported the story. The joint committee would allow potential contributors to donate to multiple pro-Romney fundraising efforts simultaneously. Donors would be able to donate up to $2,500 to Romney's primary and general-election campaigns, $30,800 to the RNC and up to $40,000 to state Republican parties,...