Anyone looking for an indication of how dramatically the American political landscape has changed since September 2008, when the global economy slid into its meltdown, should consider this: The proposal floated recently by President-elect Barack Obama to spend at least 5 billion over just two years to stimulate the moribund economy ­– with the largest share of the money slated for infrastructure projects aimed at repairing crumbling roads, bridges, sewers and the like — is drawing no serious political opposition, even from conservatives who not long ago would have railed against such a massive spending increase. To win even broader support for the proposal, Obama advisors announced a plan this week to include about 0 billion in tax cuts for workers and businesses.…