You can tell how big a deal the race to replace U.S. Sen. Pete Domenici is by looking no farther than your TV set.

Heather Wilson and Steve Pearce, both Republicans now in the U.S. House of Representatives, have prime-time ads airing on all local stations.

And the seemingly incessant attacks and character ads are on cable channels, as well.

This back-and-forth is unlikely to slow down ahead of the June 3 primary — and then comes the general election.

Wilson or Pearce in November will face U.S. Rep. Tom Udall of Santa Fe, whose lack of Democratic opposition is allowing him to keep his powder dry. And you can bet there will be plenty of crossfire between the nominees and various political groups.

National pundits see the Senate vacancy here as one of the major seats in play. Both national parties and various interest groups promise to infuse millions of dollars into this race.

Democrats hope to capture a position that the Republican Domenici has held since 1973. Their goal is to expand a slim 51-49 edge in the Senate and move closer to the filibuster-proof total of 60 Democratic senators. Republicans, naturally, are determined to hold it.

Even if Democrats win the White House and maintain their control in the House, the Senate could remain a stumbling block for Democratic initiatives — unless the party makes sufficient gains there.

The political dominoes in New Mexico started to topple when Domenici, the longest-tenured U.S. senator in state history, announced last fall he wouldn't seek re-election because of an incurable brain disease.

The result: a primary for voters statewide that features one Democrat and two Republicans, all abandoning their House seats with hopes of moving to Congress' upper chamber.

On the Democratic side, Udall, who had gained a coveted House Appropriations Committee seat after several terms representing Northern New Mexico, initially stayed out of the Senate race, then jumped in. Albuquerque Mayor Martin Chávez was in, then out.

On the Republican side, Wilson, from Albuquerque, and Pearce, from Hobbs, both made the plunge.

On the issues

The once-chummy Republican colleagues, both military veterans, have bombarded the airwaves with attack ads as well as positive biographical pieces, each candidate trying to appeal to conservative voters in their party, generally seen as those most likely to turn out for the primary.

Pearce has attacked Wilson for missing votes while campaigning. Wilson has countered that she has a high overall attendance record and that Pearce once missed an important vote on Iraq.

In ads and during a debate in Los Alamos, the two fought over support for Los Alamos National Laboratory. Wilson ripped Pearce for his support of amendments to the energy and water appropriations bill that would have made large budget cuts at the weapons lab. Pearce answered that the energy bill was full of wasteful "earmarks" and vowed: "I will vote against wasteful spending every single time."

Wilson countered that Pearce had voted against an amendment that would have cut off all the earmarks. "You can't say you support this lab when you don't support the (Department of Energy) budget," Wilson said.

Wilson also criticized Pearce for his vote against the Homeland Security Department appropriations bill funding more Border Patrol agents. Pearce said the bill called for spending $187,000 to train each agent. The Federal Law Enforcement Training Center in Artesia receives only $21,000 per person to train agents, Pearce said. Wilson said the bill wasn't wasteful because it paid for training, salary, benefits, equipment, uniforms, background checks and other necessary items.

Pearce said he sponsored an amendment that would have paid for 4,500 new border patrol agents, which Wilson voted against. Wilson said she was opposed because it would have been funded by cutting the budget for explosives detection at airports.

More recently the two Republicans clashed over a May 15 vote on a spending bill that called for $166 billion for military operations in Iraq and Afghanistan. The House defeated the bill, thanks mainly to Republican abstentions.

Pearce voted in favor of the bill. Wilson voted "present." Pearce's campaign manager, John Billingsley, issued a statement that said: "It was a simple vote asking Congress to support and fund our troops. Steve Pearce voted yes and Heather Wilson voted present. ... Heather Wilson is clearly more interested in politics than funding the men and women who fight for our freedoms."

But Wilson, in her own news release, noted the bill contained an amendment that makes "funding of the troops conditional on their immediate withdrawal from Iraq." She was one of 132 Republicans who voted present. House Republican leader John Boehner of Ohio had asked his members to vote that way. Wilson called for a "clean" war funding bill to send to the White House.

The two also have differed over the recently passed $289 billion Farm Bill, which President Bush vetoed. In a rare twist, however, Pearce, who tends to side with Bush slightly more than Wilson, bucked the president and voted for the bill while Wilson voted against it.

Wilson, pointing out Domenici also voted against the Farm Bill, said she did so because it hurt dairy farmers. Pearce has noted other agriculture groups endorsed the bill, which he called, "one of the most important and responsible reform-oriented farm bills ever produced by Congress."

Pearce and 99 other Republicans voted to override Bush's veto. Wilson, saying the bill was full of "earmarked pork barrel projects," voted to uphold the veto.

In addition to their own advertising, outside interest groups have added to the heat in this race. The anti-tax conservative group Club For Growth has run ads here attacking Wilson as a "liberal." (Domenici, who has stayed neutral in the primary, last week called for the removal of the ad, which criticized Wilson's vote for the State Child Insurance Program, which Domenici also backed.)

A socially conservative group called Common Sense Issues hasn't run ads here, but they have conducted automated "push polls" directed at registered Republicans. Phone messages praise Pearce and lambaste Wilson and Udall.

Meanwhile the national environmental group Defenders of Wildlife, which is supporting Udall, has run ads blasting both Republican candidates for taking big contributions from oil companies and casting votes that help the industry.

The horse race

A SurveyUSA automated poll conducted May 12-14 showed Pearce ahead of Wilson by 3 percentage points — 49 percent to 46 percent. That's within the 4.8 percent margin of error. But in terms of trends, the poll represented a big leap for Pearce, who gained 12 points since the previous SurveyUSA poll in November.

Wilson, according to the poll, was beating Pearce in Bernalillo County with 61 percent to 36 percent. In the rest of the state, however, Pearce was beating Wilson with 58 percent to 36 percent. The company surveyed 439 registered Republicans.

Polls consistently have shown Udall leading either Republican in a state that has a sizable number of swing voters. The latest SurveyUSA poll, which is sponsored by KOB TV in Albuquerque, showed Udall beating either Wilson or Pearce by more than 20 percentage points. Both Republicans pull less than 40 percent in match-ups against Udall.

However, Albuquerque pollster Brian Sanderoff predicts that once the GOP primary is over, the gap between Udall and his opponent is bound to tighten. Whichever Republican is nominated will be a credible candidate against Udall, Sanderoff said, because both are sitting members of Congress.

In the money race — in what is expected to be the state's most expensive election ever — Wilson has been slightly ahead. Campaign finance reports filed in April showed Wilson with $1.2 million in the bank and Pearce with $854,164. Both were well behind Udall.

Whoever wins the Republican face-off is expected to have a big fight ahead against the popular Udall, who as of April had squirreled away $2.6 million for the general election.

The money gap is bound to tighten too, Sanderoff said. "Once the primary is over, the money will flow from all sides."

In what can only be seen as a blow to Wilson, Domenici has said he won't make an endorsement in this primary, even though political wags have speculated for years that Wilson was his choice to replace him.