McConnell versus Bevin was supposed to be the big establishment/tea party war this year but McConnell turned it into a rout weeks before election day. Brat versus Cantor ended up being a rout for the tea party but that result caught everyone by surprise, including tea partiers. Tonight’s the first and last campaign of the season where both sides have gone all in — the 2008 GOP ticket is on opposite sides — and the outcome’s in doubt as voters go to the polls. If McDaniel wins, it’ll be just the third time a Republican incumbent’s been bounced in a primary since 2009. If Cochran wins, it’ll be … depressing.

If you need a quickie primer on this race, take three minutes to sift through last night’s Quotes of the Day. Senate Republicans have ante’d up for Cochran knowing that a loss makes it more likely that they’ll be primaried too. Most polls show McDaniel ahead, two of them by eight points or more, but (a) none of those polls was taken by a major nonpartisan pollster and (b) Cochran’s last-ditch strategy involves turning out Democrats, an X factor that wouldn’t show up in surveys of the GOP electorate in Mississippi. So long as you didn’t vote in the Democratic primary earlier this month, you’re eligible to vote in tonight’s GOP runoff — regardless of party registration. That’s why Cochran’s campaign, backed by the GOP establishment inside and outside of Mississippi, has doubled down on calling McDaniel an “extremist.” Most people thought they’d take it easy on McD in the runoff for fear of badly wounding a guy whom they’ll probably be stuck with as their nominee. Instead, Cochran went scorched-earth on him, hoping to convince Dems (especially black Democrats) that McDaniel represents racist tea partiers who’d surely choke off the federal spending that the state’s subsisted on for decades. Harry Enten:

Cochran has made a concerted effort to reach out to African-Americans, who make up 37 percent of Mississippi’s population, although usually less than 5 percent of Republican primary voters.

In most other states, Cochran’s effort might seem odd. Why would Democratic-leaning voters want to choose the Republican candidate who hasn’t won less than 60 percent of the vote in any of his five previous re-election campaigns? Because the chances of a Democratic victory in the fall are slim, no matter whom Republicans nominate. Mississippi’s electorate is inelastic. As I have previously noted, 80 percent of white voters in the state are likely to vote Republican. And because whites make up the majority of voters, Democrats have a narrow path to victory.

Cochran is hoping that black voters recognize this and show up at the polls. If they do, it will be most obvious in Holmes County (to the north of the capital city of Jackson) and Claiborne and Jefferson counties (which are to the southwest).

Obvious strategic dilemma for Dems: Would your nominee stand a real chance against McDaniel in the fall, or are you doomed to lose in a state this red and therefore are better off losing to Cochran? Some black pastors have settled on the latter view. The obvious strategic dilemma for Republicans is what happens to turnout in the fall after a race this nasty, especially if Cochran ends up winning on the strength of Democratic support. Would tea partiers stay home rather than vote for a nominee chosen by the other party? Would Cochran voters stay home if McDaniel ends up winning because they refuse to support an “extremist”? The Democratic nominee in Mississippi this year is an underdog but not a pushover. And an awful lot of money’s been spent making hard feelings in the losing camp tonight even harder.

Polls close in Mississippi at 8 p.m. ET. You can follow results at RCP, Politico, or my election site of choice, Ace’s Decision Desk. The only other major race tonight is in New York, where another congressional dinosaur’s resisting extinction caused by demographic shifts in his district. Rangel’s been in the House since 1971; he just turned 84 years old; there’s zero chance he’ll be back in the majority and chairing a committee in the near future. You would think he’d be ready for retirement, but lifers like him and Cochran cling to their seats out of pride and because influential friends don’t want to have their influence diminished, not because there’s any legislative work that they feel is unfinished. It’s grotesque, but that’s American democracy for you until we get our act together on term limits. The polls in New York close at 9 p.m. ET.

Update: Prediction:

@allahpundit McDaniel by 4. BTW we will have results again on the website.

— Decision Desk HQ (@DecisionDeskHQ) June 24, 2014

Update: Hmmmm.

Cochran adviser tells me he's "encouraged" by turnout, particularly heavy in Madison Co, Hinds… lots of turnout in maj. black precincts

— Robert Costa (@costareports) June 24, 2014

Update: Will it really be over tonight?

A few sources have told me to expect a legal challenge from McDaniel and/or McDaniel supporters if he loses by slim margin.

— Daniel Strauss (@DanielStrauss4) June 25, 2014

Update: Still very early at 9 p.m. ET, but the Decision Desk sees hope for the incumbent:

Cochran is doing A LOT better than in the first round…

— Decision Desk HQ (@DecisionDeskHQ) June 25, 2014

Also this:

Hinds now at 90% (!) for Cochran. Strong evidence Afr-Americans showed up to vote in runoff for the senator.

— Josh Kraushaar (@HotlineJosh) June 25, 2014

Update: I thought the chances of Dems turning out in numbers for Cochran were low, but maybe not:

More good news for Cochran (R) from the Delta: turnout up 52.3% vs. 6/3 in heavily black Coahoma County, and Cochran at 75% vs. 67%. #MSSEN

— Dave Wasserman (@Redistrict) June 25, 2014

Turnout was up 45 percent in Cohoma County, which is 71 percent black . Great sign for Cochran.

— Nate Cohn (@Nate_Cohn) June 25, 2014

McDaniel’s strongest counties, including and especially Jones, haven’t come in yet so he’ll gain on Cochran soon. But by how much?

Update: A little good news for the challenger:

McDaniel wins Webster County which voted for Cochran in the first primary. #MSSen

— Rick Shaftan (@Shaftan) June 25, 2014

Update: It’s Cochran’s night — so far.

In completed counties and counties where more than 75% is in, Cochran is running a net-2pts ahead of the initial primary

— Nate Cohn (@Nate_Cohn) June 25, 2014

Update: Keep hope alive, McDaniel fans:

https://twitter.com/seanmdav/status/481613141764083712

Update: Jones County will need to come up very big for McDaniel:

A Cochran lead of 10K+ would probably be Jones-proof. Currently up 9235.

— Alex Burns (@alexburnsNYT) June 25, 2014

Update: Two-thirds of Jones County is now in. McDaniel leads big, but not big enough:

Jones: 68.4% reporting McDaniel 6655 to 1616 for Cochran… Don't believe that's good enough for Chris McDaniel.

— (((Harry Enten))) (@ForecasterEnten) June 25, 2014

Worrisome for McDaniel: Jones County coming in but he’s winning by less than in round one. And not winning the lead. #mssen

— Dave Weigel (@daveweigel) June 25, 2014

Update: Food for thought:

https://twitter.com/TheAmishDude/status/481608740559265792

Update: The Decision Desk has seen enough:

We are calling the race for Cochran #MSsen at 9:57pm

— Decision Desk HQ (@DecisionDeskHQ) June 25, 2014

Let’s see how long it takes MSM outlets to follow suit.

Update: Dave Wasserman of the Cook Political Report follows suit:

My 10:01PM projection: GOP Sen. Thad Cochran (R) has defeated Chris McDaniel (R) in the #MSSEN runoff.

— Dave Wasserman (@Redistrict) June 25, 2014

Update: Wow:

In primary, McDaniel won combined Hinds-Jones by 3929 votes. Now, Cochran winning them 4456 votes. #mssen

— Daily Kos Elections (@DKElections) June 25, 2014

Update: Still a glimmer of hope for McD fans?

87% reporting in Mississippi and Cochran's lead is now down to 2600 votes, 50.4% to 49.6% over McDaniel

— Jamie Dupree (@jamiedupree) June 25, 2014

Update: Now Wasserman’s having second thoughts:

Ok, I'll admit, I'm getting kind of nervous about #MSSEN. McDaniel has closed gap w/ some big DeSoto precincts & still has some Jones left.

— Dave Wasserman (@Redistrict) June 25, 2014

Update: Down to the wire:

With 94.2% in, it's Cochran 50.2%, McDaniel 49.8% ~1200 vote margin

— Zeke Miller (@ZekeJMiller) June 25, 2014

McDaniel margin in Jones+DeSoto now exceeds his June 3 performance. Netting 15774 votes out of those 2 counties.

— Alex Burns (@alexburnsNYT) June 25, 2014

Amazingly, turnout tonight has surpassed turnout in the first primary election three weeks ago. That’s how hot this race was.

Update: McDaniel’s close, but maybe not close enough:

https://twitter.com/jason_howerton/status/481630074303545345

Update: Running out of time…

Now 98% reporting. Cochran leads 50.6% to 49.4%, 4500 vote margin

— Zeke Miller (@ZekeJMiller) June 25, 2014

Update: The AP throws in the towel:

AP calls #MSSEN for Cochran

— Ben Jacobs (@Bencjacobs) June 25, 2014

Three cheers for earmarks!

Update: Double wow — Cochran’s Democratic strategy worked like a charm:

Turnout increased by 92 percent in Jefferson County, the county where black vtrs represent the largest share of eligible vtrs in the country

— Nate Cohn (@Nate_Cohn) June 25, 2014

Looking at county data, Cochran's #MSSEN win is almost entirely attributable to a large turnout increase among black voters b/t 6/3 and 6/24

— Dave Wasserman (@Redistrict) June 25, 2014

Does this mean red-state Dems like Landrieu and Pryor have a better shot than everyone thinks?