A handful of Republican big-money groups on Friday launched hard-hitting ad campaigns targeting Donald Trump that echoed Marco Rubio's Thursday night debate smack-down of the GOP presidential front-runner. The group behind what's expected to be the most expensive and sustained assault - a super PAC dedicated to Rubio called Conservative Solutions PAC - has raised about $20 million in the past week alone, sources tell POLITICO. They say the cash will power a full-frontal assault on Trump in the delegate-rich states that vote in March, starting with Tuesday's 14 Super Tuesday contests. Taken together, the wave of big-money attack ads,...