By DAVID ESPO, ASSOCIATED PRESS
WASHINGTON -- Mitt Romney and his Republican presidential rivals competed Saturday in caucuses in Kansas and Wyoming, the latest contests in a grinding campaign for the nomination to oppose President Barack Obama in the fall.
A total of 52 delegates to the Republican National Convention was at stake, 40 in Kansas and a dozen in Wyoming.
Romney, the front-runner by far in the delegate competition, padded his lead overnight when he won all nine delegates on the island of Guam and an equal number in the Northern Mariana Islands.
Romney showed strength in Wyoming counties that picked delegates earlier in the week, but did not campaign in Kansas.
Rick Santorum and Ron Paul both eyed Kansas and campaigned there in the days leading to the caucuses.
Newt Gingrich cancelled a scheduled trip to Kansas late in the week to concentrate on a pair of primaries next Tuesday in Alabama and Mississippi.
Romney began the day with 440 delegates in the AP's count, more than all his rivals combined. Santorum had 181, Gingrich 107 and Paul had 46.
A candidate must win 1,144 to clinch the Republican presidential nomination at the national convention in Tampa next August.
The Virgin Islands also had weekend caucuses.
In sparsely populated Wyoming, there were 15 county conventions during the day to pick six convention delegates. Another six were chosen earlier, with Romney winning 4, Paul one and one uncommitted.
Kansas drew more attention from the White House hopefuls, but not much more, given its position midway between Super Tuesday and potentially pivotal primaries next Tuesday in Mississippi and Alabama.
Paul and Santorum both campaigned in the state on Friday, and Gov. Sam Brownback appeared with each without making an endorsement.
In Topeka, Paul told an audience of about 500 that Kansas should be a "fertile field" for his libertarian-leaning views but declined to say how many delegates he hoped to gain.
Santorum, who hopes to drive Gingrich from the race in the coming week, lashed out at Obama and Romney simultaneously in remarks in the Kansas capital city.
"We already have one president who doesn't tell the truth to the American people. We don't need another," he said.
The former Pennsylvania senator told reporters he was confident "that we can win Kansas on Saturday and come into Alabama and Mississippi, and this race should come down to two people."
An aide to Gingrich said earlier in the week the former House speaker must win both Southern primaries on Tuesday to justify continuing in the campaign.
But Gingrich strongly suggested otherwise on Friday as polls showed a tight three-way contest in Alabama.
"I think there's a fair chance we'll win," the former House speaker told The Associated Press about the contests in Alabama and Mississippi. "But I just want to set this to rest once and for all. We're going to Tampa."
Romney had no campaign appearances Saturday. The former Massachusetts governor won six of 10 Super Tuesday states earlier in the week, and hopes for a Southern breakthrough in Alabama on Tuesday after earlier losing South Carolina and Georgia to Gingrich.
Associated Press reporters Stephen Ohlemacher in Washington, Thomas Beaumont in Alabama and Phil Elliott, John Hanna and John Milburn in Kansas contributed to this report.