Republicans are increasingly worried they will lose control of the House in the midterm elections, spurring an urgent campaign to hold the Senate with a simple message: Only the majority will ensure confirmation of conservative judges and President Trump\u2019s nominees.\r\nTo many, the Senate is emerging as a critical barrier against Democrats demolishing Trump\u2019s agenda beginning in 2019. Worse yet, some in the GOP fear, Democrats could use complete control of Congress to co-opt the ideologically malleable president and advance their own priorities.\r\nDemocratic enthusiasm is surging in suburban districts that House Republicans are struggling to fortify, causing GOP officials, donors and strategists to fret. They have greater confidence in more-rural red states that Trump won convincingly and that make up the bulk of the Senate battlefield.\r\nSenate Majority Leader Mitch McConnell (R-Ky.) and his allies are seeking to capitalize on \u00adconcerns about the House. He is leading an effort to motivate \u00adconservative voters by reminding\u00a0them that his side of the Capitol has the unilateral power to confirm federal judges to lifetime appointments and Trump administration nominees.\r\nTrump is showing a keen interest in the Senate landscape, raising money for a highly touted challenger, helping clear the primary field for an endangered senator and playfully engaging in an intraparty contest.\r\nAnd marquee Republican challengers are stepping up to run for the Senate, even as House GOP retirements pile up. The latest blue-chip recruit is Florida Gov. Rick Scott, who\u00a0launched\u00a0his challenge to Democratic Sen. Bill Nelson on Monday. Top donors are\u00a0making plans\u00a0to raise money with Scott in Washington next week. His associates have talked about potentially amassing more than $100 million for the campaign.\r\n\u201cOur donors will often say we need to do everything we can to hold on to the Senate, because there\u2019s a chance we may not be able to hold the House,\u201d said Steven Law, a former McConnell chief of staff who runs the Senate Leadership Fund, a super PAC.\r\n[Florida Gov. Rick Scott to put in face time with GOP donors ahead of possible Senate run]\r\nWhile some Republicans believe they can expand their 51-to-49 Senate advantage, simply holding the slim majority has grown increasingly more complicated. Hard-right Republicans running in Arizona and Mississippi and a competitive open race in Tennessee could lead to Democratic gains. An even better pickup opportunity exists for Democrats in Nevada.\r\nBut on the whole, the Democratic path to the Senate majority is more daunting: They are defending 26 seats to just nine for the Republicans. Trump won in 10 of the states where Democrats are playing defense. They include North Dakota, West Virginia, Indiana and Missouri \u2014 all states he won by 19 points or more.\r\nIn the House, Republicans have built their ranks on locking down seats in suburban and exurban districts. But in these areas, Democratic turnout has been high in elections over the past year, \u00adfueled by anger with Trump. If Democrats can gain 23 House seats, they will clinch the majority.\r\nRep. Tom Cole (R-Okla.) put the chances of holding the House majority at \u201c50-50.\u201d The veteran party strategist warned that \u201cthe environment could easily continue to deteriorate,\u201d and said he didn\u2019t begrudge McConnell for pitching his case for the Senate.\r\n\u201cIf I had to bet right now, I\u2019d say we lose the House,\u201d said Dan Eberhart, a wealthy oil industry executive and major GOP fundraiser raising cash for several Senate contenders. At the same time, Eberhart predicted a Republican gain of three or four seats in the Senate. He said it is \u201cgalactically important\u201d to hold the upper chamber of Congress so that Republicans can confirm nominations from the White House.\r\nMcConnell sounded similar notes Tuesday when he likened the electoral head winds to a \u201cCategory 3, 4 or 5\u201d storm. Republicans need to keep control of the Senate, because \u201ceven if we were to lose the House and be stymied legislatively, we could still approve appointments, which is a huge part of what we do,\u201d he told a local editorial board.\r\nA Republican close to the Senate leader said McConnell was laying the foundation for an argument that could appeal to right-leaning voters: A GOP Senate will confirm conservative judges. The Republican, who spoke on the condition of anonymity to be candid, predicted that more reminders about\u00a0the Senate confirmation of\u00a0Neil M. Gorsuch to the Supreme Court last year will show up in the campaign.\r\nAnd if the speculation that Justice Anthony M. Kennedy might retire this summer becomes reality, Republicans would use that as a rallying cry for keeping the Senate. \u201cOne of most important roles of senate is confirming federal judges & scotus,\u201d Sen. Marco Rubio (R-Fla.)\u00a0wrote on Twitter\u00a0on Monday. \u201cThe road to growing the senate #GOP majority runs through #Florida.\u201d\r\nScott, who framed his candidacy Monday as an outsider check to a \u201chorribly dysfunctional\u201d Washington, is\u00a0expected to be in the nation\u2019s capital\u00a0on April 19 to raise money, according to three Republicans familiar with his plans. Party power brokers have been in contact in recent days to make arrangements.\r\nMichael Steele, a former Republican National Committee chairman, said the House \u201cmay be further gone than people like to admit publicly.\u201d While many in the party worry about a Democratic House and Senate launching an endless string of hearings and investigations into Trump, Steele said he has a different concern \u2014 that Democrats will work with the president to pass legislation that Republicans won\u2019t like.\r\n\u201cTrump will cut whatever deal he can get a vote on,\u201d he said. The president, he argued, \u201cis an opportunist.\u201d\r\nAfter backing embattled Republican Roy Moore in Alabama\u2019s special election last year,\u00a0only to see him lose, Trump has put greater effort into helping more mainstream Senate contenders.\r\nHe ended a fierce Republican primary in Nevada by coaxing challenger Danny Tarkanian to abandon his bid against Sen. Dean Heller and run for the House. He raised money for state Attorney General Josh Hawley in Missouri. And he helped recruit Scott to run in Florida and Rep. Kevin Cramer\u00a0to mount a campaign\u00a0in North Dakota.\r\n[Trump nudges GOP challenger out of Nevada Senate race, aiding Heller]\r\nOn Thursday, Trump visited West Virginia for a roundtable on tax reform. At the end of his event, he conducted an informal audience poll of two Republican candidates for Senate who were seated to his left and right: Rep. Evan Jenkins and state Attorney General Patrick Morrisey.\r\n\u201cIt was fairly close,\u201d the president remarked, seeming to enjoy the political spectacle. Snubbed was a third GOP candidate, former coal executive Don Blankenship, who served a\u00a0one-year prison sentence\u00a0for conspiring to violate mine safety and health standards after an accident killed 29 miners. Republicans fear a Blankenship primary win could cost them a shot at the seat.\r\nVice President Pence has also pitched in to help Senate Republicans. He will hit the road in the coming days to raise money for Heller, who is considered the most vulnerable Republican senator up this year.\r\nPence, who has also been campaigning on behalf of House and gubernatorial candidates, is expected to travel to his home state of Indiana once the GOP nominee is chosen in the May 8 primary, a White House official said.\r\nAgainst Sen. Joe Donnelly (D-Ind.), Pence plans to level the same, \u201cJoe voted no\u201d line of attack he used against Sen. Joe Manchin III (D-W.Va.)\u00a0earlier this year\u00a0when he hammered Manchin for opposing the sweeping Republican tax law, the official said.\r\nBut a trio of seats Democrats are trying to flip from Republican control could hinder the GOP effort to save the Senate majority. In each, the White House is confronting difficult decisions.\r\nThere is growing concern among Republicans about Arizona. There, Rep. Martha McSally is in a three-way primary against former sheriff Joe Arpaio and former state senator Kelli Ward, each of whom is trying to run to McSally's right. Some Republicans have wondered whether the White House should intervene and hasten a showdown between McSally and Rep. Kyrsten Sinema, the Democratic recruit who is seen by Republicans as a real threat to win in November. Sinema's campaign said she has stockpiled a hefty $6.7 million for the race.\r\nIn Mississippi, party leaders want to stop hard-right state Sen. Chris McDaniel in a special election. Republican Gov. Phil Bryant appointed state Agriculture and Commerce Commissioner Cindy Hyde-Smith (R)\u00a0to fill retired\u00a0Republican Thad Cochran\u2019s seat and run in the special election. Trump and McConnell wanted Bryant to run. Neither has endorsed Hyde-Smith yet.\r\nDemocrat Mike Espy announced his candidacy on Friday, giving the party a solid candidate for a Southern seat. The Mississippi race has no partisan primaries before the Nov. 6 election.\u00a0Instead, all the candidates will appear on one ballot, and GOP leaders worry about McDaniel advancing to a runoff against a Democrat.\r\nIn Tennessee, White House political aides\u00a0worked to keep\u00a0Republican Sen. Bob Corker from reversing course and running for reelection. Now, they are hoping that Rep. Marsha Blackburn can outperform public polls showing her losing to former Democratic governor Phil Bredesen.\r\nStill, keeping the House is the steeper climb for the GOP. And each day, it gets even tougher. The nonpartisan Cook Political Report\u00a0moved 13 House racestoward the Democrats in its rating system on Friday.\r\nThe divergent House and the Senate outlooks have caused a kind of cognitive dissonance for Republicans. When they describe the overall mood of the party, some send mixed signals.