(CNN) - With less than four days before the Indiana Senate primary, incumbent Sen. Dick Lugar and his challenger Richard Mourdock made their closing arguments in new television ads released Friday - the final spots of a long, often-times ugly nomination battle.
"America faces serious challenges, but Hoosiers' courage and determination are unbreakable. It's this spirit that guides me every day in the Senate," Lugar says in the ad, "Spirit."
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The most senior Republican in the Senate, Lugar is fighting to keep his seat and move on to a seventh term in office. Mourdock, the state's treasurer with a large tea party backing, represents the most serious primary threat for Lugar since the senator was first elected 35 years ago.
In the ad, which makes no mention of Mourdock, Lugar touts his legislative record, highlighting his opposition to President Barack Obama's sweeping healthcare reform.
"My job has been and always will be to live up to the ideals of our state," Lugar says in the commercial, as footage shows the senator meeting with various supporters during the campaign.
Mourdock, on the other hand, did mention his opponent in his new ad, saying the incumbent senator "has spent thousands of dollars telling you things about me that he knows are not true."
"He thinks this campaign's about me, but it's not. It's not about him either. It's about America's future," he added.
Mourdock went on to say the election was about "spending less, padding down our debt and restoring opportunity and freedom."
His words mirror a main theme from Mourdock's campaign and that of other groups critical of Luar, arguing the longtime senator is a Washington senator with a key role in increased spending on Capitol Hill over the years.
"I'm Richard Mourdock and I approve this message because the truth is, it's time for new conservative leadership in Washington," Mourdock says, concluding the ad.
The commercials cap months of ads lunched by the two campaigns. Many of the spots were largely negative, symptoms of what's been one of the most heated Senate fights this primary season.
National figures have also weighed on the race. Mourdock has the backing of former Alaska Gov. Sarah Palin and former presidential candidate Michele Bachmann, while Sen. John McCain and popular Indiana Gov. Mitch Daniels are siding with Lugar.
Recent polls show the race in a dead heat, even within days before voters head to the polls on Tuesday.
If Bachmann and PALIN support Mourdock, YOu know you better run as fast as you can to the Polls and VOTE FOR LUGAR.
It's a choice between someone who is at least open to dealing with the other side and someone who follows Grover and his band of merry haters. The choice is obvious. I think it will be the haters that prevail and that's unfortunate
36 years is far too long to be serving in Congress. Career politicans from ANY party hurt the country. We need to change the course of this country AWAY from a cradle to grave entitlement society that the Democrat Party has built. You know when the government is giving out thousands of free cell phones that things need to change.
You know, we never have annual deficit problems until Republicans come in and start giving away tax cuts, which always target the same demographic.
Why do Republicans have to lie about job creation to justify their tax cuts? If they feel some folks pay too much in taxes and deserve a lower rate, then just come out say so. Why all of the skullduggery about job creation and trickile down the middle class? The Bush administration demonstrated that 'trickle down' is hogwash, and is actually damaging to the economy as a whole when enacted too aggressively.