DETROIT: After a week in which Rick Santorum's presidential campaign often seemed focused on issues like pre-natal testing, abortion and religion, the message from the Republican Party's establishment was becoming clear on Friday: We've had enough.

Santorum, battling Mitt Romney in what polls say is a tight race in Tuesday's crucial primary in Michigan, sought to tilt the narrative of his campaign toward jobs and the economy Friday evening with a speech in Lincoln Park, Michigan.

Earlier, however, there were signs Santorum's actions this week - his provocative statements against abortion and contraception, his claim that Satan is attacking America and his lackluster debate performance in Arizona on Wednesday - had given some leading Republicans new ammunition in their behind-the-scenes push to see his campaign defeated.

Two opinion pieces on Friday in The Wall Street Journal - whose editorial page is typically a barometer of the thinking of the Republican Party establishment - blasted Santorum 's brand of conservatism.

One article said the former Pennsylvania senator's focus on religion and social issues could make it more difficult for the eventual Republican nominee to appeal to independent voters, the keys to victory in the Nov. 6 election.

Another article said Santorum has "potentially fatal general-election liability issues," and that his social policies - which, among other things, seek to end abortion and increase childbirth - would increase the role of government in Americans' lives. One of the key tenets of the Republican platform is to reduce government's influence on citizens.

"Voters will wonder what other values he'd seek to institute via government," columnist Kimberly A. Strassel wrote in that article.

Santorum's campaign did not comment on either article.

'ECONOMY ELECTION'

However, Santorum said last week in Ohio when questioned about his personal views against contraception that it is absurd to think that "I'm going to be the uber-czar (who is) going to try to impose that on the rest of the country."

Republican strategists acknowledge many in the party's establishment view Romney as the only one of the four remaining Republican contenders (Romney, Santorum, Newt Gingrich and Ron Paul) who could defeat Obama in November, and are hoping for a Romney victory in Michigan.

"This 2012 general election is going to be an economy election," said Steve Schmidt, who managed Arizona Senator John McCain's unsuccessful run for president in 2008.

"The reality of politics is that if your candidate and you talk about Satan and the dangers of contraception and pre-natal testing - all of those issues make it impossible to communicate a message about reforming government (and) controlling spending.

"There is not a base of people big enough to put him over the top in a general election when he's talking about all these (social) issues," Schmidt added.

That's why many establishment Republicans "are moving heaven and earth" to help Romney win Michigan on Tuesday, when Romney is also favored to win Arizona's primary, said Republican strategist Mark Pfeifle.

Schmidt and other Republicans said Santorum has also been damaged by a comment he made during Wednesday's debate, when he defended voting for a proposal he opposed because in Washington, "when you're part of the team, sometimes you take one for the team leader."

Romney, a former Massachusetts governor who grew up in Michigan, pounced on that comment as proof of his claim that Santorum has been a free-spending Washington insider.

PLAYING TO EMPTY SEATS

Romney has had his own awkward moments throughout the primary season. His campaign produced a couple more Friday during his speech before the Detroit Economic Club at Ford Field, the 65,000-seat home of the National Football League's Detroit Lions.

Romney spoke from a podium on the 30-yard line of the football field as the crowd, mostly men in suits, were seated in chairs set up on the artificial turf. It seemed an odd choice for a venue because even though more than 1,000 people attended, the stadium had an empty feel.

Romney, a former private equity executive who has taken some criticism in Michigan because he opposed an $81 billion federal bailout widely credited with helping save the auto industry, emphasized his Michigan roots and love for the cars produced by the state's auto industry.

He pointed out that he drives a Ford Mustang and Chevrolet pickup truck, and that his wife, Ann "drives two Cadillacs, actually" - a comment that analysts said could alienate some blue-collar voters by reminding them of Romney's vast wealth.

During his speech, Romney declared himself the Republican presidential candidate with "the only chance" to defeat Obama.

The primaries in Michigan and Arizona are important preludes to the "Super Tuesday" contests on March 6, when 10 states will hold presidential primaries or caucuses.

Romney said that if elected he would seek lower taxes, deep budget cuts, deficit reduction and entitlement reform which taken together would spur a burst in job growth.

"I'm not promising that every day will be easy, or there won't be sacrifice," Romney said. "But I am promising that every day things will get better."

AD WARS IN MICHIGAN

Michigan's importance in the state-by-state battle for the Republican nomination is evident in the wave of TV and radio ads swamping residents this week.

Romney's campaign has spent at least $1.7 million in Michigan on ads, according to a media buyer who tracks Republican campaign ad placements.

Restore Our Future, an independent pro-Romney "Super PAC," or political action committee, has invested at least $2.3 million in TV ads, mailings and phone calls that criticize Santorum.

As of Thursday night, Santorum's campaign had spent $800,000 on radio and TV ads in Michigan, according to a Republican media buyer. The Red, White and Blue Fund, a pro-Santorum Super PAC, had spent another $1.7 million on TV and direct-mail ads, and phone calls

.Copyright Reuters, 2012