A fresh set of polls out this week and last have Republicans more confident than ever that, while questions over which party will control the House majority after the midterms still loom, they will likely lock up not just control of the Senate majority but a strengthened majority to boot.

The GOP currently has 51 seats in the Senate, while Democrats and independents who caucus with Democrats hold 49 seats–meaning Republicans, walking into Nov. 6, cling to the slimmest of majorities ahead of the midterms. But because of the map of seats that are on the ballot this year, and the fact that many of them include red state Democrats up for re-election in states President Donald Trump won against Democrat Hillary Rodham Clinton in 2016, Republicans have been able to channel their energies less into defense and more into fighting to pick up as many seats from Democrats as possible.

There are four Senate seats–those in Texas, Tennessee, Nevada, and Arizona–that are currently GOP-held that are viewed as competitive going into this midterm. In two of them–Texas and Nevada–the incumbent Republican senator is running for re-election. In Arizona and Tennessee, new candidates have emerged. In each of these four races, with the possible lone exception of Arizona, recent polling seems to indicate Republicans will hold them all.

Texas is particularly interesting because Sen. Ted Cruz (R-TX), a 2016 GOP presidential primary rival of Trump, faces a well-funded challenge from Rep. Robert “Beto” O’Rourke (D-TX). O’Rourke has smashed fundraising records, and polls earlier in the campaign seemed to suggest that the flashy Democrat who openly embraces impeachment of Trump, if elected, has a chance at dethroning the first-term incumbent political heavyweight Republican Cruz. But, since President Trump held a come-together rally with Cruz in Houston–which was attended by tens of thousands, with more than 100,000 RSVPs, leaving thousands outside unable to get in–polling has swung back in Cruz’s direction.

A new survey released on Tuesday evening from CBS11/Dixie Strategies, in fact, found Cruz has pulled over the 50 percent mark to 52 percent and commands a double digit lead of ten percent over O’Rourke’s 42 percent, with five percent were undecided. The poll of 588 likely Texas voters was conducted Oct. 25 to Oct. 26, and had a margin of error of 4.04 percent. The survey is not an outlier. According to the RealClearPolitics polling average, O’Rourke has led throughout the campaign, but he has been soundly behind Cruz for all of October as Cruz’s lead over O’Rourke has not been within the margin of error in polling in over a month.

Texas is hardly the only bright spot for Republicans after a mid-September Senate picture scare. Back in Tennessee, where Rep. Marsha Blackburn (R-TN)–the GOP nominee for the seat being vacated by retiring Sen. Bob Corker (R-TN)–has pulled comfortably ahead of her Democrat opponent former Gov. Phil Bredesen. Despite an endorsement from pop star Taylor Swift, and what turned out to be an empty promise from Bredesen that if he were a senator that he would vote for the confirmation of now Supreme Court Justice Brett Kavanaugh, Bredesen has basically fallen off the map in recent polling in Tennessee.

Polls over the spring and summer into September that showed Bredesen leading Blackburn terrified Republicans, who were counting on holding this reliably red Senate seat to bolster their majority in November. But around the time Kavanaugh was confirmed by the U.S. Senate, Blackburn had stormed back out in front, taking a double-digit lead of 14 percent in one poll.

Blackburn’s position atop Bredesen in the race seems to have solidified in the weeks since, as a new survey out on Tuesday evening shows the conservative firebrand congresswoman with a five percent lead over the leftist Bredesen in the final days. The NBC News/Marist poll that shows Blackburn with a 51 percent to 46 percent lead represents a 7-point swing in her direction from the last time NBC polled Tennessee back in late August. The poll, conducted Oct. 23 to Oct. 27, surveyed 471 likely voters and has a margin of error of 5.1 percent.

Meanwhile, in Nevada, the most recent survey per the RealClearPolitics polling average came a few weeks ago, putting Sen. Dean Heller (R-NV) seveb percentage points ahead of his Democrat challenger Rep. Jacky Rosen (D-NV). Heller is averaging a nearly two percent lead in the race, which is no small feat, since Nevada is the one state with a GOP incumbent senator up in 2018 that Hillary Clinton won in 2016.. Nevertheless, Heller seems to be succeeding in running his race–and top pundits on both sides seem to think Heller will pull off another tough win just like he did last time he was on the ballot.

Arizona is a slightly different story. For the seat being vacated by retiring Sen. Jeff Flake (R-AZ), polling has been all over the map in the contest between Republican nominee Rep. Martha McSally (R-AZ) and Democrat nominee Rep. Kyrsten Sinema (D-AZ). The RealClearPolitics polling average currently gives Democrat Sinema a narrow and negligible advantage over Republican McSally, but it is a gap McSally has closed in recent weeks thanks to a number of strong showings in some polls.

The momentum, however, appears to be on McSally’s side as recent undercover video has emerged of Sinema’s campaign manager making a variety of pro-gun control comments in contravention of the people of Arizona’s wishes. That’s not to mention a number of cringeworthy videos of Sinema herself bashing the people of her own state as–among other things–the “meth lab of democracy.”

If Republicans hold each of the aforementioned seats, as they appear likely to do, they will retain their majority in the U.S. Senate for sure–and will start at 51 seats when they march into Democrat territory to add to their current majority, bolstering prospects of pushing conservative ideas in line with President Trump’s agenda through the Senate.

In North Dakota, polling over the month of October has been abysmally bad for Sen. Heidi Heitkamp (D-ND). The Democrat, running for re-election against Republican Rep. Kevin Cramer (R-ND), has dropped behind by double digits as far back as early October during the Kavanaugh battle. Heitkamp has not only struggled to explain away her vote against the confirmation of Justice Kavanaugh, she then released–without consent–in campaign materials the identities of a number of sexual assault victims, including details of their cases. The scandal has engulfed Heitkamp’s campaign, precluding any late comeback efforts as a new poll out Tuesday evening shows Cramer hanging on to a nine percent lead over Heitkamp in the closing days of the campaign.

The Trafalgar Group survey, of 1,498 likely voters with a margin of error of 2.1 percent, found Cramer’s 49.4 percent leading Heitkamp’s 38.5 percent. Another 5.1 percent are leaning Cramer’s way, seven percent are leaning Heitkamp’s way–leaving little room for the struggling incumbent Democrat to regain any lost ground in the final days before the midterms election next Tuesday.

In Indiana, Republican Senate nominee businessman Mike Braun has surged ahead of incumbent Democrat Sen. Joe Donnelly (D-IN), again after the troubled Democrat incumbent voted against Kavanaugh’s confirmation for the Supreme Court and as a migrant caravan bears down on the U.S. border with Mexico. Braun’s lead of at least a few points has hardened in a series of recent polls the past week or so, ensuring the Republican has surged at exactly the right moment with just days to go before Hoosiers vote next week.

In the Show-Me state of Missouri, Republican Senate nominee and Attorney General Josh Hawley has pulled ahead of incumbent Democrat Sen. Claire McCaskill (D-MO) in a number of polls this past week or so, enjoying a new consistent lead of at least a few points. President Trump is on his way to Missouri to help Hawley seal the deal, but McCaskill may actually finish herself off: Her closing argument is that she is not one of those “crazy Democrats.” When asked by Fox News’s Bret Baier to explain what she meant by those “crazy Democrats,” McCaskill disavowed her own party’s base–and bashed Sens. Bernie Sanders (I-VT) and Liz Warren (D-MA):

The crazy Democrats are people who walk in restaurants and scream in elected officials’ faces. The crazy Democrats are — we have a state senator here in Missouri that advocated for the assassination of President Trump. That’s a crazy Democrat. I don’t do those things. I am not somebody who thinks we should ever be uncivil.

If Republicans hold those four GOP-held seats, and pick up the seats in Missouri, Indiana, and North Dakota, they would have 54 seats in the Senate. But that’s not all of the GOP’s opportunities still left on the board: Recent polling in Montana and in Florida shows neck-and-neck U.S. Senate races respectively between Republican challenger state auditor Matt Rosendale and incumbent Democrat Sen. Jon Tester (D-MT); and GOP challenger Gov. Rick Scott and incumbent Democrat Sen. Bill Nelson (D-FL) in both states. In fact, in Montana, Tester–like McCaskill just did in Missouri–bashed the Massachusetts Democrat Sen. Warren, and down in Florida, Nelson is struggling to keep up with the energetic Scott on the campaign trail as he keeps nipping at his heels from minuscule leads inside polls’ margins of error.

Adding those two seats to a repertoire of all the aforementioned Senate races would catapult the GOP to 56 seats in the U.S. Senate next year when the new Congress elected on Nov. 6 is seated. And that does not even begin to mention other potential opportunities, like in West Virginia where polling shows an erratic race between incumbent Democrat Sen. Joe Manchin (D-WV) and GOP challenger Attorney General Patrick Morrisey – or Ohio where a surprisingly closer-than-expected race exists between incumbent Democrat Sen. Sherrod Brown (D-OH) and GOP challenger Rep. Jim Renacci (R-OH) – or even New Jersey where businessman and GOP senate candidate Bob Hugin could potentially upset longtime Democrat Sen. Bob Menendez (D-NJ) as the Democrat there faces corruption charges.

Republicans also have shots in Senate races in other states Trump won in 2016 – like Pennsylvania, Michigan, and Wisconsin, though those are further out of reach than these other battles – or even in one of the two Minnesota U.S. Senate seats where recent polling showed appointed Sen. Tina Smith (D-MN), who was picked for the slot after disgraced former Sen. Al Franken (D-MN) resigned, clinging to a slim lead just outside the margin of error in one poll.