Four states are holding primary elections on Tuesday.

The primaries will determine which Republican and Democratic candidates will stand in November’s midterm elections.

Two of those states are Arizona and Florida.

Voters in Florida, the number one battleground state in the nation, will pick a Democratic candidate for the US Senate and a Republican candidate for governor.

Their opponents for the general election in November are running unopposed.

Anti-incumbent wave

We went to a breakfast meet and greet with Gubernatorial candidate Rick Scott in Plant City, Florida, near Tampa.

Scott is a billionaire former healthcare executive who is trying to ride the anti-incumbent wave to the governor’s mansion.

Susan MacManus is a professor of political science at the University of South Florida.

She says, "People are so mad at what’s happening in Washington, it’s affecting how they look at everything else, from the US Senate race to the County Commissioner.

"A lot of them have the perspective of anything’s better than what we’ve got now."

As its name indicates, Plant City is an agricultural town. 

Scott was there telling voters how, if elected, he’d help businesses start hiring again, lower taxes, and reduce regulation.

But he spent a lot of his speech beating up on his opponent.

He didn’t mention Bill McCollum, the state attorney general, by name, but he did tell voters, "You have a clear choice… If you believe career politicians are running our state well and everything is going well in Tallahassee, then you should vote for my opponent."

Economy factor

The main issue in Florida is the economy. The recession hit hard here.

Florida has one of the highest unemployment rates in the country.

Tourism has taken a big hit because of the oil spill in the Gulf of Mexico, and the housing market is still in a slump.

MacManus says, "It is all about money and the future economically.

"The new governor is going to have to tackle jobs and the economy above anything else."

Scott has spent nearly $40m of his own money to try to win.

That’s led his opponent to say he’s trying to buy the election.

But longtime politician McCollum and his political allies have managed to raise nearly $14m to fight Scott.

Polls show the race is too close to call.

Mud slinging

Voters have been barraged with negative ads by both candidates.

I asked Scott about the negativity of the race, and he defended his campaign.

He says, “What we’ve done is talk about our message of getting out and talk about jobs.

"That’s what our primary message is, so I’m very comfortable with that, that’s what’s going to work."

But even his supporters at the breakfast meet and greet said they’d had enough.

Amy from Plant City says, “I’m tired of it.  They need to focus on the issues. Stop slinging mud and focus on the issues.”

Whoever wins on Tuesday will face Democrat Alex Sink and Independent candidate Bud Chiles.

But for now, Scott and McCollum are campaigning feverishly across Florida to be the one who will fight on until November.

Poor campaign

The other must-watch Primary is in Arizona.

After serving nearly 25 years in the US Senate, Republican John McCain is facing a challenger who, months ago, looked like he could knock the veteran legislator off.

Widespread public anger with Washington, and the resurgence of the right wing of the Republican Party, led former Congressman JD Hayworth to challenge McCain.

McCain has spent more than $20m to keep his seat.

And he’s changed some of his positions on issues like immigration and climate change to appeal to more conservative voters.

Polls show the longtime senator will almost certainly keep his job.

Hayworth was really no match for the man once called a maverick.

He’s run a poor campaign and had few ideas beyond criticism for McCain.

Now analysts are calculating the damage McCain has done to his political legacy by abandoning his moderate positions and elevating Hayworth as a real threat to his job.

There will be more on Tuesday's primaries at 0100GMT on Al Jazeera English TV.