WASHINGTON – The Senate approved a Democratic budget plan Friday that promises a balanced budget in five years by mixing spending increases with partial renewal of expiring tax cuts. The $2.9 trillion budget outline won approval on a 52-47 vote, but only after Democratic moderates rewrote it to favor extending several popular tax cuts that are to expire at the end of the decade. The most immediate impact would be to sanction big spending increases when lawmakers later this year write budget bills for the Pentagon and domestic Cabinet agencies. The vote was a victory for Senate leaders who viewed passing a budget as a key sign of Democrats’ ability to govern. The vote was mostly along party lines, though two Republicans joined the Democrats in backing the plan, Sens. Olympia Snowe and Susan Collins of Maine. Congress failed to pass a budget last year, and Democrats didn’t even bring one to the floor when controlling the Senate in 2002. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! The Democratic blueprint is nonbinding but sets guidelines for follow-up legislation. It also would require that lawmakers seeking to cut taxes or boost benefit programs – such as Medicare, children’s health care or farm subsidies – to “pay for” the changes with tax increases or offsetting spending cuts. The budget suffers, however, from some of the same flaws Democrats see in Bush’s February budget plan. Like Bush, the Democrats left out funding for the long-term costs of the war in Iraq and for fixing the alternative minimum tax that threatens unsuspecting middle-class families.