With job approval numbers hovering in the mid-40s, President Barack Obama and his signature legislative achievements have become potent political assets for Congressional Republicans in their quest to flip the House and Senate in the midterm elections.

Interviews with several GOP consultants this week revealed varying strategies for trying to expose Obama’s perceived political weaknesses, depending on the districts or states their clients are running in. Some say attacking Obama personally remains too “risky,” and these operatives are advising candidates to target Speaker Nancy Pelosi (D-Calif.), Senate Majority Leader Harry Reid (D-Nev.) and the Democratic Congress. Other Republican strategists are urging clients to attack “Washington and everything associated with it.”

Yet the emerging consensus among Republican strategists — which they attribute to a read of private and public polling of individual House and Senate races — is that victory on Nov. 2 will require targeting Obama directly. Democratic operatives concede the president’s weak numbers but dispute the GOP’s claim that this factor will negatively affect their candidates. Obama’s average national job approval rating from Aug. 5 through Monday was 45.3 percent, with 50.7 percent disapproving, according to RealClearPolitics.com.

In some districts and states, polling shows Obama to be unpopular enough that GOP consultants are targeting him with a rhetorical sledgehammer, crafting advertising and messaging that attempts to tie the Democratic candidate to the president. In others, the attacks are subtle and nuanced, with a focus on criticizing Obama administration policies while offering the Republican candidate as a means to apply a “check and balance” against the White House and Congressional majority.

Congressional Republicans have, at least for now, opened up a solid lead over Democrats on the generic question of which party’s candidate voters plan to support this fall.

But one Republican consultant monitoring several House races said the more telling indicator of potential GOP success in the midterms is how survey respondents answer when asked whether they plan to vote for a Democrat who will help Obama enact his agenda or a Republican who will act as a “check and balance” against the White House and the Democratic Congress.

“Voters are not just unsatisfied with either, but with a monopoly that they believe has to be broken up,” this Republican strategist said. “This is really where the fall campaign will be contested.”

In fact, Senate Republican leaders have employed the “check and balance” argument for several months. Before departing for the August recess, Senate GOP Conference Chairman Lamar Alexander (Tenn.) gave his colleagues a messaging cheat sheet that read: “Check and Balances — on an overreaching Washington government with too much spending, too many taxes, too much debt.”

Now, however, that argument is being picked up by some Republican strategists who are advising House candidates, with the argument likely to become a major theme of Republicans running for the House and Senate over the remaining two and a half months of the campaign.

“Republicans are focused on the issues the American people care about the most: jobs, spending and debt, and terror. We are committed to serving as a check and balance on an overreaching Washington government that spends too much, taxes too much, and borrows too much,” Alexander wrote in the messaging packet that he sent home with Senate Republicans earlier this month.

Democratic National Committee spokesman Brad Woodhouse almost dared Republicans to target Obama directly, warning that such a move would backfire by motivating his party’s base to turn out and support him against such attacks. Woodhouse also sounded confident that the Democratic strategy of making Nov. 2 a choice between the past and the future, rather than a referendum on Obama, would prove successful.

“A big part of midterm elections are about motivating the base, and if Republicans want to motivate our base by going after President Obama, who remains extremely popular among Democrats, that’s their decision to make,” Woodhouse said. “The truth is, President Obama is just getting started making the choice in this election clear for the America people. As we get closer to November, this election will become a choice between Democrats who are moving the country forward and Republicans who want to take us back to the Bush era rather than a referendum on any one person or party.”

Obama’s job approval rating is higher than where President George W. Bush stood just before the 2006 elections, when Democrats flipped both chambers of Congress, but just below President Bill Clinton’s standing in November 1994, when Republicans did the same. Republicans need to win a net of 39 House seats and 10 Senate seats to regain control of Congress in this year’s midterm elections.

According to Gallup, Bush in the final days of the 2006 campaign registered just 38 percent approval, with 56 percent disapproving. Voters down the stretch of the 1994 midterms were split on Clinton, with 46 percent approving and 46 percent disapproving. In 2006, Democrats won a net of 31 House seats and six Senate seats; in 1994, Republicans won a net of 54 House seats and eight Senate seats.

In some districts, particularly those that Obama did not carry in 2008, his disapproval numbers have become “toxic,” on par with where Bush was in 2006 — in the high 50s or 60s, according to a Republican operative familiar with the House playing field. “That doesn’t give them the turf where he can go,” the GOP operative said. “Whether a candidate runs directly against the president in commercials depends on the district.”

Republican consultants advising House candidates are more likely to feel confident running directly against Obama than those advising Senate candidates. But even among GOP strategists with clients running for the House, their view on running against the president might be determined by where in the country they are.

One Republican consultant based in California is advising his House candidates to avoid targeting Obama and is instead urging them to go after Pelosi, even on matters of policy, such as health care reform, that have become defined by the president. In some quarters, the health care reform law is referred to simply as “Obamacare.”

“While his policies are very unpopular, running against him is a high risk because voters in the middle still hope he succeeds,” the California-based GOP consultant said. “I am telling all of my clients to run against Pelosi, not Obama. It’s the Pelosi health care takeover, the Pelosi failed stimulus, the Pelosi debt, etc.”

A Washington, D.C.-based Republican monitoring Senate races said attacking Obama directly is likely to fall flat in the president’s home state of Illinois, where Rep. Mark Kirk (R) and state Treasurer Alexi Giannoulias (D) are battling for the president’s old seat. But it’s a different story in other states, such as Indiana, Kentucky, Missouri and Pennsylvania, the Republican said.

“His approval numbers there are a real problem for the Democrats,” the D.C.-based GOP operative said.

However, Democratic strategists note that their candidates are outperforming Obama in several contested races. In states such as Missouri, where a recent poll showed Obama with 34 percent approval, Democrat Robin Carnahan was at 42 percent, 6 points behind Republican Roy Blunt in the open-seat race for Senate. In the Kentucky Senate race, a recent survey had the president at 41 percent, 3 points better than Democrat Jack Conway, who nonetheless trailed Republican Rand Paul by only 3 points.

Democrats following House races — and those monitoring Senate contests — pointed to the May special election in Pennsylvania’s 12th district as evidence that the GOP strategy of targeting Obama will fail. Sen. John McCain (R-Ariz.) beat Obama in that Democratic-leaning district in 2008, but now-Rep. Mark Critz (D) won the heavily contested special with a strategy of going local even as Republicans tried to nationalize the race into a referendum on the president’s policies.

“House Republicans test-drove this strategy of using President Obama as a bogeyman in the Pennsylvania special election in a district where the president’s approval rating was in the mid-30s and their strategy crashed and burned,” Democratic Congressional Campaign Committee spokesman Ryan Rudominer said.

But Republicans generally believe that the political atmosphere for Democrats has poisoned well beyond where the dissatisfaction was in May, particularly among independent voters, who continue to abandon Obama in polls.

And even though they acknowledge that the GOP retains brand dissatisfaction of its own, they argue that voters will support Republican candidates because their unhappiness with the direction of the country and the 9.5 percent unemployment rate — as well as their desire to put a “check and balance” on the Democratic White House and Democratic Congress — will override any lingering concerns they have about the potential for GOP governance.

Some Republican consultants view the magic recipe for success as running against Obama’s policies and his handling of his job as president. In the view of these strategists, Obama still retains some personal goodwill, so the key to victory on Election Day is to make sure a candidate’s criticism revolves around the president’s agenda and his leadership of the country.

These Republicans contend that polling shows Obama’s policies to be “wildly unpopular” and becoming more so every few weeks. “You can see the dial moving,” according to one consultant with Senate clients, who added that the electorate’s opinion is unlikely to change significantly between now and Nov. 2.

Another Republican operative, this one based in Texas, said the president’s numbers are extremely unfavorable when tied to the policies that he has pushed since assuming office 19 months ago. This fits with the policy-driven “check and balance” critique strategy that has been gaining ground among House and Senate GOP strategists.

“It’s difficult to run against Obama on a personal front,” the Texas-based GOP strategist said. “The question, ‘Do you approve or disapprove of the way Barack Obama is handling his job as president on X issue?’ Here’s where he’s toxic. You can basically pick an issue and you’ll see heavy unfavorables on this front.”