The frontrunner in the Republican Party's race to select an opponent to face U.S. President Barack Obama in November's election, Mitt Romney, was seeking a boost in his campaign Saturday and he got one.

The former Massachusetts governor came out on top in a straw vote of participants at a Washington convention of conservative Republican activists . Romney won 38 percent of the vote. Former senator Rick Santorum, coming off Tuesday's victories in contests in three states to the west , got 31 percent.

Results from a caucus vote in Maine are due later Saturday. Romney is facing a challenge in that northeastern state from another candidate, Texas Congressman Ron Paul, who has yet to win any of the previous Republican party contests. Both men spent Saturday campaigning for votes in Maine's caucuses.

So far Romney has won the votes in New Hampshire, Florida and Nevada. He lost to former House Speaker Newt Gingrich in South Carolina and to Santorum who won the first contest in January in Iowa.

The Tuesday's losses to social conservative Santorum have highlighted Romney's struggle to gain the support of the conservative Republican base. On Friday, he sought to change that by calling himself “severely conservative” in a speech at the CPAC meeting.

After Maine, the four presidential contenders face primaries later this month in Arizona and Michigan — the state where Romney was born and raised.