Senate Republicans are preparing an aggressive rebuttal to President Barack Obama’s State of the Union address, with plans to use Wednesday evening’s speech as a pivot point to launch a direct appeal to the voters to return the GOP to power in November.

Although the chamber’s Republicans are bracing for another year of acting as a legislative firewall between a Democratic Congress and the president’s desk, they have decided they must also focus on a positive agenda as the midterm elections approach.

“Now it’s about giving people not only a reason to vote against the Democrats, but a reason to vote for Republicans, like Scott Brown did in Massachusetts,— a senior Republican Senate aide said Monday.

In the wake of Brown’s stunning 5-point victory over state Attorney General Martha Coakley (D) in the special election to fill the late Sen. Edward Kennedy’s (D) seat, the White House signaled no intention to change course. (Brown is expected to be sworn into office this week.)

Obama on Friday said he remains committed to passing comprehensive health care reform, and administration officials suggested on the Sunday morning talk shows that the president would not use the nationally televised, prime-time address to reveal a scaled-back domestic agenda.

That strategy will be strongly rebutted by Senate Republicans, although they might look more favorably at job-creation initiatives Obama is expected to unveil.

“I don’t think the American people are going to be too happy if that’s the tack he takes,— Senate Minority Whip Jon Kyl (R-Ariz.) told reporters about Obama’s hopes for health care reform. “I think they’ve been sending a message — first in Virginia, then New Jersey and now Massachusetts. I think it would be a mistake for him not to heed that message: Cut back on the grandiose plans.—

Kyl was referring to November GOP victories in the New Jersey and Virginia gubernatorial races, as well as Brown’s win last week.

With Brown’s election, the Republicans control 41 seats and once again have the ability to sustain a filibuster. In fact, Brown campaigned on being the 41st GOP vote to kill the Democratic health care bill, and his victory has effectively killed the bill and stalled Obama’s reform drive.

Republican strategists caution that this new dynamic puts more of an onus on Senate Republicans to offer detailed alternatives to the president’s agenda and not fall back on simply opposing him, regardless of how unpopular his signature policies might be. But that does not mean Senate Republicans need to soften their tone, nor are they expected to if Obama delivers the State of the Union they predict.

“I think they’ll be more aggressive,— said a GOP operative who works downtown. “But I also think they will start to articulate clear-cut alternatives.—

That effort began Monday as Republican leaders took to the Senate floor to begin framing Obama’s speech in politically advantageous terms and laying out their alternative vision for solving the nation’s problems.

Senate Republican Conference Chairman Lamar Alexander (Tenn.) urged Obama to focus his speech on economic concerns and terrorism and to avoid the urge to “veer too far to the left— in his plans for the coming year.

“To reconnect with the American people in his State of the Union address, creating jobs should be President Barack Obama’s first subject, reining in the national debt his second and terrorism his third,— Alexander said while also repeating the GOP’s growing insistence on an incremental approach to policy issues rather than the sweeping wholesale reform efforts Democrats have attempted over the past year.

“In my view, a step-by-step job strategy for the country should include tax cuts, less regulation, certainty, free trade, a balanced labor climate, good educational opportunities and clean but cheap energy,— he said.

Minority Leader Mitch McConnell (R-Ky.) was expected to give two floor speeches ahead of Obama’s speech, one today and one Wednesday.

According to GOP aides, McConnell plans to use one speech to address economic issues — including the national debt, federal spending and the need to increase jobs — while the other speech will focus on national security and terrorism. McConnell will use the speech to lay out “what he wants to hear— during the speech, one source said.

Republican strategists who work in the Senate view Obama’s State of the Union as the real beginning of the campaign season and the start of the GOP’s efforts to rebuild after losing 14 seats in 2006 and 2008 and watching Sen. Arlen Specter (Pa.) defect to the Democratic Party early last year.

A Republican political strategist who advises GOP Senate candidates said the advice being given to both challengers and incumbents is to remind voters of the Democrats’ attempts to push legislation that has proved unpopular over time — in addition to offering a positive, contrasting agenda.

“The Democrats’ determination to ram through unpopular policies through partisan votes has clearly backfired, and if they plan to double down on that strategy they should expect Republicans to reap the political benefits in November,— the GOP political strategist said.

John Stanton contributed to this report.