OSKALOOSA, Iowa (AP) — The slugfest between Republican presidential frontrunners Mitt Romney and Newt Gingrich is escalating, as the two sparred from a distance with attack ads that have come to dominate the volatile contest.

The rift underscores the contrasting campaign styles of the two men as they ready their final pitches to voters in Iowa and New Hampshire. And it left each decrying a new campaign finance system — fueled by deep- pocketed political action committees — that each benefits from.

Campaigning in Iowa

In Iowa, Gingrich vowed his White House bid would remain positive, while in the next breath he labeled the Romney camp’s tactics “disgusting.” The former House speaker, known for a bareknuckles campaign style when he engineered the GOP takeover of the House in the 1990s, suggested at a campaign stop on Tuesday that his opponents “hire consultants who get drunk, sit around and write stupid ads.”

Romney protested that he couldn’t control the independent PAC expenditures, but pointedly declined to disavow the ads.