NEW YORK - August 24, 2010 - Five states - Alaska, Arizona, Florida, Oklahoma and Vermont - go to the polls Tuesday, but only three of them can point to primary elections that are being closely monitored by a national audience.

In Alaska and Arizona, incumbent Republican Senators Lisa Murkowski and John McCain face vigorous challenges from the right. In Florida, the open Senate and gubernatorial contests have attracted self-funding outsider candidates whose free-spending candidacies are testing the resolve of each party’s political establishment.

Alaska Senator Lisa Murkowski was smart enough to see this one coming. Restlessness at the conservative grass roots, residual anger toward her over her original appointment to the Senate in 2002 and the involvement of the Palin family in support of her Tea-Party-fueled foe, Joe Miller, put a variety of combustible elements into play, but the first-term GOP senator was prepared for it.

Going by the polls, the air wars and certainly the media coverage, Arizona GOP Senator John McCain should be headed for a blowout victory over former Rep. J.D. Hayworth. McCain has spent $21 million - more than he’s spent in all his Senate campaigns combined since winning the seat in 1986 - to bury his primary challenger under an avalanche of ads labeling Hayworth a “huckster” and defending his own position on immigration. McCain spokesman Brian Rogers even labeled Hayworth “deader than Elvis” on Monday. There’s little chance McCain will lose his seat in either the primary or general election, but if Arizona voters don’t hand him a double-digit win over Hayworth, it’ll be a sign of just how deep conservative reservations about McCain still run.

Even against a crowded backdrop of competitive state elections this year, Arizona’s open 3rd District stands out. One reason is the candidacy of Ben Quayle, the 33-year-old son of former Vice President Dan Quayle, the early front-runner who has faded as his campaign got embroiled in recent controversy.

But Quayle’s not the only Republican in the crowded open-seat primary whose performance Tuesday will be closely watched. There are State Senator Pam Gorman, whose weapons proficiency was touted in a campaign video that went viral on the Internet, and Vernon Parker, a Tea-Party-backed African-American candidate who is vying to join a GOP conference in Washington that currently has no black members.