More than just the presidency is at stake tonight. The battle for which party will control the Senate is coming down to the wire, too — and now with Sen. Pat Toomey’s win in Pennsylvania, Democrats dreams of regaining the Senate are over.

Going into tonight’s election, Republicans held a 54-seat majority in the Senate and are now looking to hold onto that majority. Democrats needed to pick up an additional four seats to regain majority control of the Senate provided Clinton won (five seats if Trump won, because the vice president breaks Senate ties as the 51st vote), but were unable to do so.

A quick guide to the eight competitive Senate races we watched most closely

There were 34 Senate races this year, but only eight had a reasonable chance of a seat switching from one party to another. There were four races where Democrats led in the polls and four where Republicans were ahead. Most of them were very close, with the exception of the Illinois race between incumbent Sen. Mark Kirk (R) and challenger Rep. Tammy Duckworth (D), where Duckworth handily beat Kirk.

Democrats managed to hold onto Nevada, but only picked up one seat from Republicans

Nevada , a Democratic open-seat contest where Rep. Joe Heck (R) ran against former state Attorney General Catherine Cortez Masto (D) was called in Cortez Masto’s favor. Prior to the release of the 2005 tape where Trump bragged about sexual assault, Heck had led Cortez Masto in the polls, but after renouncing his support for Trump (which was met with boos), Cortez Masto was able to earn enough votes to allow Democrats to hang onto Nevada.

, a Democratic open-seat contest where Rep. Joe Heck (R) ran against former state Attorney General Catherine Cortez Masto (D) was called in Cortez Masto’s favor. Prior to the release of the 2005 tape where Trump bragged about sexual assault, Heck had led Cortez Masto in the polls, but after renouncing his support for Trump (which was met with boos), Cortez Masto was able to earn enough votes to allow Democrats to hang onto Nevada. Illinois, where Kirk lost the seat to Duckworth. Throughout the Illinois race, Duckworth led Kirk in the polls, but only in recent weeks did her lead break double digits. Duckworth’s victory gave Democrats one of five seats they needed to pick up to regain control in the Senate.

In other key “toss-up” Senate races, Republicans came out strong

Indiana , a Republican open-seat contest where Rep. Todd Young (R) defeated former Sen. Evan Bayh (D). This was the most competitive race of the seven toss-ups, with only a 0.7-point polling spread separating Todd from Bayh.

, a Republican open-seat contest where Rep. Todd Young (R) defeated former Sen. Evan Bayh (D). This was the most competitive race of the seven toss-ups, with only a 0.7-point polling spread separating Todd from Bayh. North Carolina , where incumbent Sen. Richard Burr (R) defeated former state Rep. Deborah Ross (D).

, where incumbent Sen. Richard Burr (R) defeated former state Rep. Deborah Ross (D). Wisconsin , where incumbent Sen. Ron Johnson (R) defeated challenger Sen. Russ Feingold (D) with 52 percent of the vote. Aside from the Senate race in Illinois, which was declared a Democratic win, the Senate race in Wisconsin was the Democrats’ next best chance for victory.

, where incumbent Sen. Ron Johnson (R) defeated challenger Sen. Russ Feingold (D) with 52 percent of the vote. Aside from the Senate race in Illinois, which was declared a Democratic win, the Senate race in Wisconsin was the Democrats’ next best chance for victory. Pennsylvania , where incumbent Sen. Pat Toomey (R) defeated Katie McGinty (D) with 48.9 percent of the vote. McGinty won 47.2 percent and Libertarian candidate, Edward Clifford won 3.9 percent.

, where incumbent Sen. Pat Toomey (R) defeated Katie McGinty (D) with 48.9 percent of the vote. McGinty won 47.2 percent and Libertarian candidate, Edward Clifford won 3.9 percent. Missouri, where incumbent Sen. Roy Blunt (R) defeated Missouri Secretary of State Jason Kander (D) with 49.6 percent of the vote. Kander won 46.2 percent and Libertarian candidate, Jonathan Dine won 2.4 percent.

New Hampshire hasn’t been called yet, but that won’t change the balance of power in the Senate

New Hampshire, where Sen. Kelly Ayotte (R) has a narrow margin over Gov. Maggie Hassan (D). Votes have only been counted from 94 percent of precincts, so there is a possibility that Hassan could still win, but with Ayotte wining 48.1 percent of the vote compared to Hassan’s 47.8 percent, it seems as if Ayotte will hold onto her seat.

There were 26 additional seats up for election — but none of these seats changed parties. Louisiana could still switch, but we won’t know until December and it won’t make a difference to Democrats

The rest of the Senate races didn’t switch parties this year. This includes 16 seats held by Republicans and nine held by Democrats. We still don’t know the outcome of the Senate race in Louisiana as it has moved to a run-off that will be decided in December.

The open seat of Sen. David Vitter (R) could now end up Democrat, but it still won’t matter for Democrats when it comes to control of the Senate. The two candidates on the Louisiana ballot to fill Sen. David Vitter’s (R) open seat are Louisiana state Treasurer John Kennedy (R) and Foster Campbell (D).

But this wasn’t always the case: Up until a few weeks ago, Senate seats in Florida, Arizona, and Ohio were seen as pretty competitive races. The races only began to open up in recent days.

In Florida, Sen. Marco Rubio (R) had a 3.7-point lead over challenger Patrick Murphy (D) heading into election day. And in the other two states, incumbent Republicans John McCain and Rob Portman both enjoyed double-digit leads over their opponents, securing easy Republican victories.

Watch: Why Democrats are in trouble even if Clinton wins