Senate Democrats have assembled a laundry list of possible tax hikes to help finance their $3.5 trillion spending bonanza, according to an internal committee document obtained by The Post. Many Democrats are eager to implement the host of corporate and individual tax hikes to fund the $3.5 trillion plan, but Beltway insiders are dubious the more controversial plans — like taxing share buybacks and hefty executive payouts — will make the final bill.... ...Sen. Mike Crapo, a Republican of Idaho, said in a statement to The Post that he had “serious concerns” about the Democratic “tax-and-spending spree.” He said the...