Presidential Race Moves West On Tuesday To Arizona, Utah And Idaho

White House hopefuls are heading West on Tuesday as both parties face voters in Arizona and Utah, while Democrats will caucus in Idaho.

For Republicans, it's another chance to try to stop Donald Trump's mounting delegate advantage, and the states voting Tuesday aren't necessarily the friendly terrain he has been used to.

On the Democratic side, Vermont Sen. Bernie Sanders is trying to rebound from last week's Mega Tuesday sweep by former Secretary of State Hillary Clinton that only contributed to his delegate deficit.

Here's what to watch in each state:

Arizona

This could be the most interesting state to watch on both sides; results are expected after 11 p.m. ET.

For Republicans, the state's 58 winner-take-all delegates are the biggest prize of the night. Polls have shown Trump has a lead, but some observers in the state believe that gap could be closing.

Trump has made immigration a pillar of his campaign, and his forceful stance has attracted the support of controversial Sheriff Joe Arpaio and former Gov. Jan Brewer.

But it's a closed primary, and Cruz has done better when just registered Republicans are casting ballots.

Early voting also is prevalent in the state, though, so Cruz may not be able to fully benefit from the shrunken field. Cruz hopes to win over Hispanic voters in the state — Trump won those voters in Nevada but was crushed by Marco Rubio with that voting bloc last week in Florida.

For Democrats, Clinton has the edge. She won the state in 2008 and she has also done better than Sanders in closed Democratic contests. What little polling there is gives her a sizable lead, and she should perform well with Hispanic voters over Sanders.

Utah

Trump isn't expected to win here, largely due to the real estate mogul's unpopularity with Mormon voters, who make up a majority of the Utah GOP electorate. He lost big to Cruz in Idaho and Wyoming, other states with a significant Mormon bloc, and the Texas senator also has the backing of Utah Sen. Mike Lee and Gov. Gary Herbert.

2012 GOP nominee Mitt Romney, who now lives in Utah, has said he will caucus for Cruz, and he's even recorded robocalls urging people to vote for Cruz, saying that "a vote for John Kasich is a vote for Donald Trump."

How well the Ohio governor does in Utah could have big implications for how many delegates Cruz is able to get. Polls have shown Cruz with a big lead, but if he is able to top 50 percent in the state, he'll get all of the state's 40 delegates. But if Kasich gets enough to hold Cruz below that, then Trump could also pick up delegates proportionally.

On the Democratic side, this is another state that should be a good fit for Sanders, given its whiter electorate and the fact it's a caucus. Polls have shown him with a slight lead over Clinton in the fight for the state's 33 delegates. Sanders has had massive turnout at rallies in the state in the closing days.

Idaho

Only Democrats will caucus in the Gem State on Tuesday (Texas Sen. Ted Cruz won the state's GOP primary two weeks ago).

Twenty-three delegates are up for grabs here, where caucuses end at 9 p.m. ET. Sanders held a rally in Boise on Monday — even forgoing speaking at pro-Israel lobby AIPAC's Washington, D.C., gathering this week to campaign in the state — and he hopes the state will be friendly territory for him. Sanders has done better than Clinton in caucuses this cycle, and Idaho is a state she lost handily to President Obama in 2008.

There's been scant polling in the state, but one survey predicted a tight race.