Republican presidential race possibly grows by three

On Friday three conservative Republican congressman said they are exploring presidential runs, further crowding the field at a time when many party activists say they are looking for a true conservative choice.

Ron Paul of Texas and Duncan Hunter of California filed paperwork with the Federal Election Commission to form presidential exploratory committees. Tom Tancredo, of Colorado, is traveling to Iowa this weekend and says he is thinking about running for president.

Last fall, Tancredo said he would not run because his pet issue, immigration, was getting attention. If he does enter the race, he is expected to be highly critical of Senator John McCain's immigration position, which allows for a temporary guest worker program and permits those here illegally to remain if they pay fines. They would have to go "to the end of the line" behind those who have applied for citizenship.

Ron Paul ran for president before as a Libertarian.