With Democrats poised to unify around whomever secures their party’s nod for president, Senate Republicans this week said they were ready to put aside differences with their sometimes-maverick colleague Sen. John McCain (Ariz.) and rally around an agenda that focuses on issues where there is no distinction: the war in Iraq and fiscal discipline.

Indeed, McCain’s allies and detractors alike said that if he secures the GOP presidential nomination, McCain is likely to advance some policies that run counter to the Republican mainstream. Plus, as the general election nears, he could look to entice independent and conservative Democrats to his campaign — a move that could cause difficulty for Congressional Republicans as they look to show themselves as a viable alternative to the Democratic majority.

But McCain’s GOP colleagues said the growing likelihood of his nomination means even those conservative Senators — and some in the Republican base establishment — who oppose some of his positions recognize they need to come together on a broader party agenda that best arms them to take on the Democrats in November. The most likely themes, they said, would be related to national security and fiscal discipline — two areas where Republicans generally and McCain in particular have been champions.

“We need to come together, we’ve got to strive for that,” said Sen. Mel Martinez (R-Fla.), who recently endorsed McCain.

“If we don’t, obviously, a divided party never wins,” he added. “The other side is going to be formidable. All we have is to pull together to try to win.”

Sen. Norm Coleman (R-Minn.) added, “Just because we fight today, doesn’t mean we can’t come together tomorrow.”

Coleman had supported former New York Mayor Rudolph Giuliani before he dropped out of the race and now has endorsed McCain.

Coleman and Martinez are two of McCain’s 45 House and Senate backers, a share of whom were behind McCain’s candidacy even when his presidential hopes were left for dead last summer. But McCain also has Congressional adversaries — some personal and some political — after serving for more than two decades in the chamber and making deals with Democrats on politically toxic issues like campaign finance reform and immigration.

Sen. John Cornyn (Texas), the GOP Conference vice chairman who has sparred with McCain at times, said that despite the disagreements, he believes party unity won’t be elusive with McCain atop the ticket. That’s because Republicans will have the most powerful unifying force of all — the opportunity to take on liberal Democrats like Sen. Hillary Rodham Clinton (N.Y.) or even Sen. Barack Obama (Ill.), he said.

“He’s very strong on a lot of things that the base cares about,” Cornyn said of McCain.

Asked whether the party can shelve long-held differences with McCain and see eye to eye on a 2008 agenda and message, Cornyn said: “We’re definitely going to have to.”

“We’ll all find our way together,” Cornyn said. “But the base needs to understand what the alternative is if our nominee doesn’t win. They need to understand what the alternative is.”

It was unclear at press time whether McCain would capture enough delegates in the Super Tuesday primaries to essentially wrap up the Republican presidential nomination. But heading into the 21 GOP contests, McCain had the momentum and a double-digit lead in most public opinion polls over his nearest rival, former Massachusetts Gov. Mitt Romney.

Either way, Republican Senators already are anticipating a McCain victory and how his general election platform would fit with theirs heading into a critical election year. Most reminded that McCain — while sometimes unpopular — has been a strong fiscal and social conservative throughout his career, and has been one of the most forceful advocates for President Bush’s war policy.

“There’s enough agenda items that our Conference and the nominee are strongly aligned on,” said a Senate Republican leadership aide. “And we know the Democrats are going to be strongly aligned with their nominee [on those things] — that will take up 90 percent of our time.”

This aide added that even though McCain has riled the base at times, Congressional Republicans are likely to be more heavily focused on undercutting Sens. Clinton or Obama, who “either way is north of Ted Kennedy on the liberal scale.” Plus, the staffer noted that Congressional Republicans spent most of the last seven years largely working “in lock step” with President Bush, so “maybe it doesn’t hurt to not have a lock-step story in the next eight months.”

“Yeah, there are things he’s going to have to bridge and issues he’s going to have to deal with,” the leadership aide said. “But he’s 360 degrees better than Obama or Clinton.”

Senate Democrats say that whether Clinton or Obama wins their party’s nomination, they think they have far less fence-mending before them than the Republicans, who in recent days have increased their attacks on McCain’s conservative credentials. In many ways, Democrats have had difficulties pointing out the policy differences between Clinton and Obama, even as the race narrows and the stakes grow.

Several Democratic Senators — even those publicly aligned with one of the candidates — said they believe there will be little separation this year between their ultimate presidential nominee’s message and agenda and that of their Conference. And Democrats universally expressed optimism that any recent spats between Clinton and Obama will be long forgotten once the electorate chooses the Democrats’ White House pick.

“I think Senators are going to appreciate a nominee has a bully pulpit to drive our agenda,” said Sen. Ron Wyden (D-Ore.), who is neutral in the race.

“On balance, either candidate can do that,” added Sen. Sheldon Whitehouse (D-R.I.), who has endorsed Clinton. “It’s important there be enough of us on the same page to overcome the obstructionism we’ve seen out of the Republicans so we can get things done.”

Whether Democrats will unite around their nominee quickly will have to play out, but many Congressional Republicans say they believe McCain — if he wins the nomination — will reach out and do his part to try to galvanize the party moving forward. If nothing else, McCain has established relationships and an open line of communication with many of his colleagues on Capitol Hill.

Sen. Lamar Alexander (R-Tenn.), formerly a backer of Sen. Fred Thompson but now neutral, said he sees “no reason whatsoever why Congressional Republicans can’t work with him.” But Alexander said McCain will be assuming a new role if charged with the duty of carrying his party’s mantle as the 2008 presidential nominee.

“Instead of being the lone wolf, he will be the leader of the pack,” Alexander said. “It will require different skills.”

Sen. John Thune (R-S.D.), a conservative lawmaker who has been one of McCain’s most ardent supporters, said McCain is “going to have to pick things out that he’s been involved in but that are popular with base voters and put together an agenda that gets a majority of Republicans on board.”

Thune predicted that McCain would work with Senate Republicans to come up with a handful issues that not only unite their party but also have broad appeal heading into November. McCain may not be able to win over some of his Republican adversaries, Thune conceded. But even so, his Arizona colleague may be the only GOP candidate who can make up for any deficits by bringing in new voters critical to holding onto the presidency.

Said Thune: “He gives us our best chance of appealing to moderates and independents and attracting a broad coalition.”