Tom Perriello, left, shakes hands with Lt. Gov. Ralph Northam at the start of the first debate of Virginia's Democratic candidates for governor at Lanier Middle School on Saturday, April 29, 2017, in Fairfax, Virginia.

(CNN)Both major parties will hold primaries in Virginia's gubernatorial race, the first time they've held the contests on the same day in the commonwealth's history.

The vote will be the first statewide political contest since the election of President Donald Trump, and the controversial early days of his administration loom large over the contests on both sides of the aisle.

Establishment vs. insurgency

Both contests feature established candidates with lengthy political careers facing off against insurgent, populist candidates hoping to upset the power bases of their respective parties.

The Democratic contest has proven to be more competitive, with former Rep. Tom Perriello feeding off the enthusiasm of liberals ready to send Trump a message. Perriello has earned the support of prominent national democratic leaders, but Lt. Gov. Ralph Northam retains the support of the state party apparatus.

The race has been framed as a reboot of the Bernie Sanders-Hillary Clinton contest, but the comparison is not a perfect fit. Northam has pushed his campaign further to the left and has described Trump as a narcissistic maniac -- while Perriello has attempted to reach out to Trump voters by selling a message of economic populism framed through a progressive perspective.

On the Republican side, former George W. Bush aide Ed Gillespie is building off the goodwill he established with Republicans after his narrow loss to Sen. Mark Warner in 2014. Gillespie has successfully tiptoed around the presence of Trump, embracing his policies that are popular with Republicans without directly tying his campaign to the President.

It hasn't been easy. Flame-throwing challenger Corey Stewart, the chair of the Prince William County Board of Supervisors, has touted his former role as the Trump campaign chairman and has challenged Gillespie to pledge his allegiance to Trump. Stewart has waged a campaign to protect Confederate monuments around the state and was the only candidate to not outright reject an alt-right rally in Charlottesville organized by white nationalist Richard Spencer.

Gillespie has basically ignored Stewart, and the strategy has worked. Most polls show Gillespie with a double-digit lead. A third candidate, State Sen. Frank Wagner, has struggled to gain traction, despite winning the endorsement of The Washington Post's editorial board.

Turnout

Primaries for state level elections in Virginia are known for their notoriously low turnout, despite the fact that the vote is open to all registered voters. Turnout in 2017 could be an important key in this race because the insurgent candidates on both sides are likely banking on the fact that many voters that don't normally participate will this time around.

That will be especially important for Perriello, who is counting on a wave of Democratic enthusiasm and is running without the benefit of the party infrastructure. Polls have shown that Perriello has a slight lead in the race, but that lead may be contingent on unreliable pools of voters who usually sit primaries out.

The energetic candidate is hoping his effective media strategy and relentless campaign schedule (he spent the weekend before the primary on a 24-hour get-out-the-vote swing) will turn the tide. A little more than 319,000 Democrats turned out in a three-way primary in 2009. Absentee ballot applications are up significantly as compared to previous gubernatorial elections, which could indicate a higher than usual overall turnout.

A variety of Virginia politicos to whom CNN spoke peg the magic number at 375,000 voters -- above that number could be good for Perriello, but below that should indicate a Northam win.

Which endorsements matter

In the closing days of the Democratic primary race, Northam will appear multiple times with Virginia's powerful trio of popular statewide elected Democrats. Warner, Gov. Terry McAuliffe and Sen. Tim Kaine have stuck by the lieutenant governor, whom all three have known and served with for a long time.

That show of support should matter to the politically tuned-in primary electorate. But Perriello has the support of popular national figures. He's currently running a TV ad that features Massachusetts Sen. Elizabeth Warren, Vermont Sen. Bernie Sanders and former President Barack Obama singing his praises. Sanders and Warren have formally endorsed Perriello in this race, though Obama has not. It is the kind of ad that could compel a Democrat who normally only participates in presidential contests to make the effort to vote in Tuesday's primary.

Gillespie, meanwhile, has locked in support from Republican Party leaders from top to bottom in Virginia, but what he doesn't have -- and what he hasn't sought -- is the support of the sitting Republican president.

In 2009 and 2013, Obama not only endorsed but held rallies in support of the Democratic candidates in Virginia. That was, of course, after the primary, but there is no sign Gillespie will be in search in the same kind of lift from Washington in 2017. Trump is not only a polarizing figure, but Virginia was one of the few swing states he lost.

Stewart, despite the fact that his run is in many ways a clone of the Trump campaign, also does not enjoy the support of the President. But that hasn't stopped him from embracing the President, his policies and his persona while reminding primary voters of Gillespie's careful maneuvering around Trump.

Corporate influence

Perriello is outright rejecting the support of one of the most powerful political entities in Virginia, the state's public utility, Dominion Energy. Dominion has long been a major donor to both Republicans and Democrats, and in 2017, the company has donated to both Northam and Gillespie's campaigns.

But not only did Perriello not take their money, he has vowed to stop the company's efforts to build pipelines in the state. Northam has taken a more cautious approach on the pipeline, calling for a rigorous review before they are built without outright rejecting the proposal. Perriello is hoping Virginia progressives view his move as a signal that he will rid corporate influence from the governor's mansion -- a task that will be much easier said than done.

National reaction to the outcome

No matter what happens on Tuesday, national political prognosticators are going to attempt to draw a grand conclusion on what the result tells us about American voters in the era of Trump. Chances are those conclusions will be a stretch. We may get a glimpse of Democratic enthusiasm, but it will still be an incredibly small sample size. The Virginia primary electorate is fickle, unpredictable and varies greatly depending on the year. Any attempt to use the results as a basis for predictions about the direction of the country are at best premature. It may not even offer much of a signal about what to expect from Virginia voters in November.