The prospects for President Barack Obama's $447 billion jobs plan grew dimmer Monday as he unveiled the fine print of how it would be paid for—primarily through tax increases that Republicans said would destroy jobs, not create them.

Mr. Obama proposed limiting itemized deductions for families with taxable income of $250,000 or more a year, ending tax breaks for oil companies and corporate jet owners, and cutting out a tax break for investment-fund managers. The White House says the tax changes would take effect in 2013 and...