Senate Democrats are very worried about losing big in the 2018 midterms. Here's the proof.

The 2018 midterm elections will be critical for determining the party in power through the next several election cycles. Will Republicans maintain power or is the political pendulum swinging in Democrats' favor?

Tight polling in many states means that question won't be settled until Election Day in November. But one thing is for certain: Democrats will be on the defense because, of the 33 Senate seats up for grabs, Democrats hold 22 of them, while Republicans hold just eight. Independents hold the other two.

Democrats are apparently so worried, they're already calling in the big guns: former President Barack Obama, Hillary Clinton and her husband, former President Bill Clinton.

What are the details?

Sen. Chris Van Hollen (D-Md.), chairman of the Democratic Senatorial Campaign Committee, admitted last week Democratic candidates running for Senate already welcome the support of Obama and the Clintons.

"We welcome support from everybody who wants to help, including Secretary Clinton and President Obama," he said, according to the Washington Examiner. "As the head of the DSCC, we welcome those individuals and everybody that wants to help."

According to Hollen, Clinton has already been reaching out to campaigns. The twice failed presidential candidate started "Onward Together" last year, an organization focused on electing Democrats nationwide.

"I think she's going to continue to reach out to candidates and let them know that she's ready to help in any way that she can. These are really conversations that go on between Secretary Clinton or President Obama and the particular campaign," Van Hollen said.

What about the House?

Every seat in the House is up for grabs each election cycle, and if Democrats want to re-take control of the House, they have some work to do. Republicans currently have a 42-seat majority.

But according to the New York Times, Democrats in California running for the House are very discombobulated. The Times reports:

National Democrats, confronting mushrooming political chaos across Southern California, are pouring millions of dollars into congressional races to avert a self-inflicted disaster that could undermine their chances at taking control of the House.

Essentially, at least in California, there are so many Democrats running in important primaries that the national party fears losing seats, or just not being competitive as Republicans are much more organized.