There are 6 key races that could help Democrats take back the US Senate
Composite image of Sen. Joni Ernst (R-IA), Sen. Susan Collins (R-ME), Sen. Martha McSally (R-AZ), Sen. Cory Gardner (R-CO), Senate Majority Leader Mitch McConnell (R-KY) and Sen. Thom Tillis (R-NC) via screengrabs

There are 23 Republican Senators up for reelection in 2020 and Democrats only need to win three to tie the Senate and four to take over.

A Wall Street Journal report detailed the key races that Democrats can actually win if they hunker down and get Democratic voters to the polls.

New Mexico is the only open seat this election and President Donald Trump thinks that he'll be able to win the state of New Mexico, but he'll have to find 70,000 more voters to be able to make it happen.

In Colorado, North Carolina, Arizona and Iowa, Trump's approval will be critical to Republicans surviving, but the coattails aren't what they once were. In Colorado, things look terrible for the president. Polls show him losing not only to every Democratic candidate, but it shows depressed Republicans are less likely to turn out to vote in 2020.

Cory Gardner is in deep trouble in Colorado, where he has a favorability of just 40 percent and unfavorability of 39 percent. A serious Democratic challenger will link Gardner to Trump and show voters how he's hedging his bets, trying not to anger the president and hold onto his seat. When asked whether it is wrong to ask a foreign government for election help, Gardner refused to answer five times.

North Carolina has finally been outed for their partisan congressional maps, which could ultimately add several new Democrats to the House. That battleground where Democrats will run powerful and well-funded campaigns that are likely to be successful could also depress GOP turnout in the state. As of mid-October, Trump's approval rating began to slip in the state, to below 40 percent from 44 percent in 2018. The loss comes from Republicans too.

"Nearly three-quarters of Republicans said they approve of the job Trump is doing, the poll shows. But that compares to previous approval ratings among Republicans in the 'mid-to-upper 80,'" said The News & Observer.

Thom Tillis is having a rough time within his own party. While he still hovers over 50 percent approval with the GOP, that's a 12 percent drop. Outside of his own party, things look worse. Tillis has among the lowest approval ratings for Republican senators in the United States at just 33 percent.

Arizona is on the brink of a massive shift in their support for Democratic candidates. With the GOP's hostility to people of color and immigrants, the heavily Latino state put Trump even with all leading Democratic candidates for president. While the state doesn't support impeachment (50 percent) Trump's state-wide job approval is underwater with 50 percent disapproval and 45 percent approval.

Martha McSally (R-AZ)  is among the top two Republicans in swing states that are endangered, The Journal said. She was placed in Sen. John McCain's old seat after losing her race in 2018 to Rep. Kyrsten Sinema.

Currently, retired astronaut Mark Kelly took the lead over McSally in an August poll by five points.

In Iowa, it seems impossible that a Democratic presidential candidate could prevail, but Trump has a 47 percent disapproval rating to his 44 percent approval.

Over a year ago, Sen. Joni Ernst wasn't doing bad in her approval rating, but things have changed. As of October, she's lost 9 percent in her approval rating, dropping her below 40 percent. It is "the biggest slide in net approval for any senator between the second and third quarters of 2019," said Morning Consult.

Trump's strategy in the past has been to go into areas where he's extremely unpopular and to fight to mobilize what few supporters are still there. But it has the added disadvantage of mobilizing Trump's opposition. While Trump may be inclined to go campaign for the Republican senators, they likely don't want him doing huge public rallies.

“It’s clear that the president is going to have a difficult re-election path,” said Inside Elections newsletter editor Nathan Gonzales. “And that makes it more difficult for Republicans to keep control of the Senate.”

These main states also don't take into account two major U.S. Senators that have become villains over the past several years. Senate Majority Leader Mitch McConnell (R-KY) has been caught cozying up to Russians, earning him the nickname "Moscow Mitch." But more, McConnell is the source of the downfall in Washington's progress. While the House has passed over 50 bills this year, McConnell has refused to take any of them up. The U.S. Senate has done less work for Americans than any time in recent memory. McConnell even bragged about it, calling himself the Grim Reaper of legislation. McConnell has the lowest approval rating of any U.S. Senator in the country. In his own state, just 37 percent of people support McConnell, while 50 percent disapprove.

The one senator who comes close to McConnell is Sen. Susan Collins, who has gone from the most popular senator to the bottom two. "Only 45 percent of Mainers said they approved of her compared with 48 percent who said they disapproved," FiveThirtyEight wrote in July. Decades of Collins' claim that she is an independent thinker and not a Republican shill have fallen as her voting record turned to support President Donald Trump. Given that the U.S. Senate isn't voting on bills, it means Collins has no chance of improving that before the November election.