Romney wins in D.C., Wisconsin, Maryland

MILWAUKEE -- Mitt Romney tightened his grip on the Republican presidential nomination last night, sweeping primaries in Wisconsin, Maryland and Washington, D.C., with time left over to swap charges with President Barack Obama.

"Four more years?" Romney asked sarcastically as supporters cheered him in Milwaukee.

He said Obama was "a little out of touch" after spending four years surrounded by the trappings of power and had presided over near-record job losses as well as increases in poverty, home foreclosures, government debt and gasoline prices.

The victories enabled Romney to pad his wide delegate lead over Rick Santorum, who flashed defiance in the face of pressure to abandon his candidacy in the name of party unity.

Wisconsin was the night's marquee contest, the only place of the three on the ballot where Santorum mounted a significant effort. Returns from 69 percent of the state's precincts showed Romney with 43 percent of the vote to 38 percent for Santorum, 12 percent for Ron Paul and 6 percent for Newt Gingrich.

In Maryland, returns from 81 percent of precincts showed Romney with 48 percent of the vote to 30 percent for Santorum, 11 percent for Gingrich and 10 percent for Ron Paul.

With 100 percent of precincts counted in Washington, Romney had 70 percent to 12 percent for Paul and 11 percent for Gingrich. Santorum was not on the ballot.

"We won 'em all," he exulted.

Romney won at least 74 delegates Tuesday night, with 21 yet to be allocated. That pushed his total to 646 of the 1,144 needed to clinch the nomination. Santorum has 272 delegates, Gingrich has 135 and Paul has 51.

Interviews with voters leaving polling places in Maryland and Wisconsin showed an electorate more concerned with a candidate's ability to defeat Obama than with the strength of his conservatism, his moral character or his stand on the issues. Similar soundings in earlier states have consistently worked to Romney's advantage.

Voters in both states were less apt to be born-again or evangelical Christians than in most previous contests -- 34 percent in Wisconsin and 32 percent in Maryland. That, too, suggested an advantage for Romney.

Increasingly, Romney and many senior figures in his party have begun behaving as if the primaries are an afterthought, pivoting to criticism of Obama.

"He gets full credit or blame for what's happened in this economy and what's happened to gasoline prices under his watch and what's happened to our schools and what's happened to our military forces," Romney said while campaigning in Waukesha, Wis.