Republican Rubio seeks boost in Nevada, but Trump dominates polls

By Megan Cassella (Reuters) - Republican presidential candidate Marco Rubio aimed to outpoll rival Ted Cruz in Nevada's caucus on Tuesday to bolster his position as the establishment favorite for his party's nomination for the Nov. 8 election. Looming over the tight race between the two first-term Cuban-American U.S. senators is Republican front-runner Donald Trump, the billionaire businessman who has won two of the first three state nominating contests and is expected to dominate the field in N