Republican hopes of retaking the Senate have been dealt a serious blow as a couple of key races shifted in the Democrats favor.

New movement on behalf of the Democratic candidate in Indiana, combined with increasingly bleak outlooks in Maine and Massachusetts, where Sen. Scott Brown (R) is in trouble, would give Democrats three pickups in the upper chamber.

ADVERTISEMENT

That means Republicans will have to win six Democratic seats — seven if President Obama wins reelection — to retake control of the Senate, a tall task.

At this point, it may be more likely that Democrats actually gain seats than lose control in an election cycle where they were expected to be playing defense.

Here’s a look at recent movement in several key Senate races:

INDIANA:

Republican candidate Richard Mourdock has been on defense since he made controversial comments on pregnancy and rape.

"I struggled with it myself for a long time, but I came to realize that life is that gift from God," Mourdock said at a debate, after noting he believes in abortion only when the mother's life is in danger. "And I think even when life begins in that horrible situation of rape, that it is something that God intended to happen."

Democrats pounced on the remark, tying it to other Mourdock comments opposing bipartisan compromise to paint him as outside the political mainstream. According to a poll released Friday by the well-respected Howey Politics Indiana, it’s worked. Rep. Joe DonnellyJoseph (Joe) Simon DonnellyWatchdog accuses pro-Kavanaugh group of sending illegal robotexts in 2018 Lobbying world Trump nominees meet fiercest opposition from Warren, Sanders, Gillibrand MORE (D-Ind.) leads Mourdock by 11 points — 47 to 36 percent.

“It’s all over but the crying. Joe Donnelly is poised to succeed Republican Sen. Richard Lugar in the U.S. Senate,” GOP pollster Christine Matthews, who helped conduct the poll, wrote in Friday’s edition of Howey Politics Indiana.

The race could tighten – Mourdock’s campaign insists it’s still ahead, and an 11-point lead seems large — but his remarks are likely the last impression voters will take to the polls.

NEBRASKA:

Democrat Bob Kerrey’s surge in recent polling has shaken Republicans’ confidence in a pickup, as state Sen. Deb FischerDebra (Deb) Strobel FischerFormer Nebraska Sen. Bob Kerrey endorses Biden Lawmakers toast Greta Van Susteren's new show Statue of Chief Standing Bear to be unveiled in Capitol MORE’s (R) lead has shrunk from double digits to just 3 percentage points in a recent independent poll from the Omaha World-Herald at 49 to 46 percent support.

That steep drop in support since September indicates Kerrey's attacks on Fischer's involvement in a land dispute may be working.

Outside groups have jumped back on the air in recent days, a sign they see a tightening race. The GOP group American Crossroads recently launched a major ad buy for the last days of the campaign, as did the Democratic group VoteVets.

Kerrey also rolled out a big-name endorsement that he hopes will boost his bipartisan bona-fides: Former GOP Sen. Chuck HagelCharles (Chuck) Timothy HagelGOP Senate candidate said Republicans have 'dual loyalties' to Israel White House aide moves to lobbying firm Overnight Defense: US, Russia tensions grow over nuclear arms | Highlights from Esper's Asia trip | Trump strikes neutral tone on Hong Kong protests | General orders ethics review of special forces MORE, still revered by many in Nebraska.

Fischer is still favored to win, but the new attention on both sides has made this race a surprising one to watch in the final stretch.

WISCONSIN:

A race that had long focused on healthcare and the economy has taken a dark turn in the closing days.

But that hasn’t moved the polls, which show one of the tightest Senate races in the country between Rep. Tammy BaldwinTammy Suzanne BaldwinFederal funding for Chinese buses risks our national security Democrats threaten to withhold defense votes over wall The Trump downturn: Trouble ahead for the US economy MORE (D-Wis.) and former Wisconsin Gov. Tommy Thompson (R).

Baldwin has embraced her party’s leaders in a state that’s leaning Democratic at the top of the ticket. She’s stumping with President Obama and Vice President Biden during their appearances in the state this week and touting an endorsement from former President Bill ClintonWilliam (Bill) Jefferson ClintonChelsea Clinton says she's not considering a bid for New York House seat Lewinsky says Trump impeachment inquiry affects her 'personally' Mellman: Which is the right question? MORE in her final ad.

In recent weeks she and Thompson have engaged in a nasty back-and-forth over national security. Ads from Thompson accused Baldwin of being soft on Iran and voting against a resolution to honor the victims of the Sept. 11, 2001, attacks, with Baldwin countering that Thompson had made millions off of the tragedy and owns stock in companies who are helping Iran develop its nuclear program.

Two recent polls both show Baldwin holding a 3-point lead, with a survey from Democratic-leaning Public Policy Polling (PPP) showing her with a 51-48 advantage and a We Ask America poll putting her up 49 to 46. 

MISSOURI:

It’s improbable that Rep. Todd Akin (R-Mo.) will shake off the stigma of his rape comments and win, but there are signs it may not be impossible.

Sen. Claire McCaskillClaire Conner McCaskillIranian attacks expose vulnerability of campaign email accounts Ex-CIA chief worries campaigns falling short on cybersecurity Ocasio-Cortez blasts NYT editor for suggesting Tlaib, Omar aren't representative of Midwest MORE (R-Mo.) lurched ahead and has held steady with high-single-digit leads over Akin since late August, following his remark that pregnancy is rare in cases of “legitimate rape” because the female body has mechanisms to prevent it. The comment caught fire and brought rebukes from most in the Republican Party.

But a poll released last weekend from the St. Louis Post-Dispatch/Mason Dixon showed him just two points behind the incumbent, at 45-43, and this week Akin has received a flood of new support from outside groups — with questions about whether the National Republican Senatorial Committee is behind one such infusion (they won't comment) after they pledged to withdraw their support from Akin.

He’s now airing more ads than McCaskill for the first time all cycle. That, coupled with President Obama’s unpopularity in the state, could be enough to push Akin to a win — but such an outcome is far from likely, and Akin’s surge and the resulting support may just be too little, too late.

OTHER RACES:

Massachusetts and North Dakota’s Senate races offer the same lesson: Sometimes even the strongest candidates can’t outperform their party.

Sen. Scott Brown (R-Mass.) faced a difficult road to reelection from the beginning in heavily Democratic Massachusetts, on the same ticket as Mitt Romney, who has posted a double-digit deficit there all cycle. He mounted a strong campaign based on his proclaimed independence and a beer-drinking everyman appeal, and managed to retain high popularity in the face of attacks on his record from Democrat Elizabeth WarrenElizabeth Ann WarrenButtigieg tweeted support for 'Medicare for All' in 2018 Overnight Health Care — Presented by National Taxpayers Union — House Dems change drug pricing bill to address progressive concerns | Top Republican rejects Dem proposal on surprise medical bills | Vaping group launches Fox News ad blitz Hillicon Valley: FCC approves T-Mobile-Sprint merger | Dems wrangle over breaking up Big Tech at debate | Critics pounce as Facebook's Libra stumbles | Zuckerberg to be interviewed by Fox News | Twitter details rules for political figures' tweets MORE.

But Obama’s coattails may simply be too long in Massachusetts, and Warren looks increasingly likely to pull through on Election Day, flipping another seat for which Republicans held high hopes.

A PPP poll puts Warren up 6, with 52 percent support to Brown's 46. A Suffolk/7News poll gives her a broader lead of 53 to 46, up 7.

In North Dakota, Democrat Heidi HeitkampMary (Heidi) Kathryn HeitkampThe Hill's Morning Report — Biden steadies in third debate as top tier remains the same Trump wins 60 percent approval in rural areas of key states Pence to push new NAFTA deal in visit to Iowa MORE walks through farmland, chats with ranchers and even hits softballs in her ads, but she may not be able to convince enough voters that she’s not a rubber-stamp for Obama, as Republican Rep. Rick Berg’s (R-N.D.) campaign has called her.

Berg’s campaign has found few other ways to hit Heitkamp, as she’s made an effort to tout her support for Republican pet projects, like the Keystone pipeline and coal and natural gas mining. The race remains a toss-up, but Obama faces a double-digit deficit in the state, one that Heitkamp may not be able to shake in time for Election Day.

A Mason-Dixon poll at the end of October gave Berg a slim 47-45 lead.

Meanwhile, both sides predict a coin-flip race in Montana, while Democrats feel good about holding onto their seat in Virginia. 

In Montana, a recent Rasmussen poll puts Sen. Jon TesterJonathan (Jon) TesterSchumer seeks focus on health care amid impeachment fever Red-state Democrats worry impeachment may spin out of control Overnight Energy: Lawmakers show irritation over withheld Interior documents | Republican offers bipartisan carbon tax bill | Scientists booted from EPA panel form new group MORE (D) up 1, at 49-48. A Virginia WeAskAmerica poll released last week showed a dead heat with former Gov. Tim KaineTimothy (Tim) Michael Kaine2020 general election debates announced Senators call for Trump administration to testify on Syria Schumer: Transcript 'absolutely validates' Trump impeachment inquiry MORE (D) and former Sen. George Allen (R) knotted at 50 percent support each.

Republicans, though, feel fairly confident about their seat in Nevada, where a recent Las Vegas Review Journal/Survey USA poll shows Sen. Dean HellerDean Arthur HellerThis week: Barr back in hot seat over Mueller report Trump suggests Heller lost reelection bid because he was 'hostile' during 2016 presidential campaign Trump picks ex-oil lobbyist David Bernhardt for Interior secretary MORE (R) leading Rep. Shelley Berkley (D) 46 to 40, and more so about Arizona, where Rasmussen has Rep. Jeff FlakeJeffrey (Jeff) Lane FlakeTrump's GOP impeachment firewall holds strong How to survive an impeachment Are Senate Republicans certain that Trump can return to office? MORE (R) up 50 to 44 over Democrat Richard Carmona.

This story was updated on Nov. 4 at 8:23 a.m.