The final primary night of the midterms takes place Tuesday, with consequential contests across New England and Delaware.  

In New Hampshire, former Sen. Scott P. Brown, R-Mass., faces a crowded GOP primary filled with hopes of challenging Democratic Sen. Jeanne Shaheen in November. Down the ballot in the Granite State, GOP primaries in House races will determine nominees in two key contests.  

Across the border in Massachusetts, Rep. John F. Tierney faces the toughest primary of his 18-year congressional career. He could be the fourth incumbent to lose re-election in a primary in 2014 — and perhaps the only Democrat (to see which members lost their primaries this cycle, check out Roll Call’s Casualty List ).  

There are also primaries in Delaware and Rhode Island, although neither state features competitive congressional races.  

Polls close in all four states at 8 p.m. You can follow live result updates on Roll Call’s “At the Races ” politics blog.  

Here’s what to watch:  

1. What is former Sen. Scott Brown’s margin in New Hampshire’s GOP Senate primary?
Brown, who crossed state lines from Massachusetts to seek the Senate in the Granite State, is expected to win the Republican nomination to challenge Shaheen in November. But he faces a crowded field of Republican opponents Tuesday, including former Sen. Bob Smith, former state Sen. Jim Rubens and a half-dozen other little-known and underfunded opponents.  

With such a crowded field, it’s worth watching Brown’s margin of victory. It could be the first sign of whether Granite State voters are troubled, or not, by Brown’s state switch.  

New Hampshire’s Senate race is rated a Democrat Favored contest by the Rothenberg Political Report/Roll Call.  

2. Will Tierney be the last incumbent of 2014 to fall in a primary?
Tierney started the cycle as one of the most vulnerable incumbents — that was because he was on track for a rematch with the Republican he narrowly defeated in 2012, former state Sen. Richard Tisei.  

But recent polling shows Tierney could lose in the primary to Iraq War veteran Seth Moulton. The challenger has spent about $1 million on a throw-the-bums-out campaign message, attacking Tierney for being an ineffective member of Congress.  

Democratic operatives still favor Tierney to win the nod, but they predicted the margin of victory will be slim — probably single-digits. In any case, it won’t be the running start Tierney — or whoever wins the Democratic nomination — wanted for the sprint to Nov. 4 against Tisei.  

Massachusetts’ 6th District is rated as a Tilts Democrat  contest by the Rothenberg Political Report/Roll Call.  

3. Will there be a re-match in New Hampshire’s 1st District — again? The GOP primary will determine whether former Rep. Frank Guinta, R-N.H., will face Rep. Carol Shea-Porter, D-N.H., for a third time. Shea-Porter picked up in the seat in 2006, but lost to Guinta four years later. In 2012, Shea-Porter defeated Guinta.  

But first, Guinta faces a primary against former University of New Hampshire Business School Dean Dan Innis, as well as two other little-known Republicans. Guinta’s familiarity with voters is an asset going into Tuesday’s contest. But a super PAC has spent more than $500,000 boosting Innis’ candidacy, which could put him over the edge.  

The 1st District is the more competitive in the Granite State. President Barack Obama carried it by a 2-point margin in 2012. Whomever wins the nod, Republicans are bullish they can oust Shea-Porter in November.

4. Can the Club for Growth get a win in New Hampshire’s 2nd District? Four Republicans are battling to take on Rep. Ann McLane Kuster, D-N.H., in the 2nd District, which tends to favor Democrats slightly. Obama won the district last cycle by a 10-point margin.  

Operatives say the primary is a tossup between state Rep. Marilinda Garcia and former state Sen. Gary Lambert.  

Garcia has the backing of the conservative wing of the GOP, including the Club for Growth and Sen. Ted Cruz, R-Texas. But privately, Republican operatives said her GOP primary opponent, former state Sen. Gary Lambert, is likely the better candidate of the two to take on Kuster in this left-leaning district.  

Neither Garcia nor Lambert are good fundraisers, and either Republican would start the general election at a severe cash-on-hand disadvantage against Kuster. The state’s late primary gives the GOP nominee little time to catch up.  

New Hampshire’s 2nd District is rated a Leans Democratic contest by the Rothenberg Political Report/Roll Call.  

Roll Call Election Map: Race Ratings for Every Seat


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