Will Sarah Palin continue string of successful endorsements this year?

Sarah Palin in October 2011. (Steve Helber - AP) DALLAS The question raised earlier this week about whether Sarah Palin is underestimated is more than a Washington parlor game.

The answer will be of great interest in Texas, where the former Alaska governor and Lone Star Gov. Rick Perry are backing different Republican Senate candidates in the states May 29 primary.

Both Palin and Perry have political baggage, of course. You may be forgiven for wondering whether its truly a blessing to be endorsed by Game Change Palin or oops moment Perry, fresh off an unsuccessful run for president.

But in Texas, two of the top candidates in the crowded field to replace retiring Sen. Kay Bailey Hutchison obviously welcome the endorsements.

Perry threw his support behind Texas Lt. Gov. David Dewhurst. And last week, Palin announced her backing of former Texas solicitor general Ted Cruz.

RedState.com was among those predicting that her endorsement will prove decisive for Cruz. But Dewhursthas been the front-runner in most polls

Palin wrote a letter to Cruz saying: Your conservative prin! ciples, passionate defense of our Constitution and our free market system come at a time when these cornerstones of our freedom and prosperity are under attack.

Our shared goal isnt just to change the majority in control of the Senate, but to assure principled conservatives like you are there to fight for us, she wrote.

Cruz responded:I am humbled and honored to have Governor Palins support as we fight to restore fiscal sanity to the circus that is Washington.

The endorsement is the latest for Cruz from prominent conservatives. Othersinclude the Tea Party Express, Sen. Jim DeMint, Sen. Rand Paul, evangelical leader James Dobson, Family Research Council Action PAC and FreedomWorks, according to a Cruz campaign Web site.

Palins endorsement comes on the heels of her role in the upset this week in the Nevada GOP primary. Palin backed lesser-known state Sen. Deb Fischer, who beat two better-known and better-funded rivals to become the nominee for a U.S. Senate seat.

That follows, of course, Palins endorsement in the Indiana GOP primary, where a lesser-known candidate, Richard Mourdock, unseated incumbent Sen. Dick Lugar.

The timing of her endorsements this year seems designed to provide a late-stage boost to the candidates. Palin endorsed Fischer a week before the primary vote. And she endorsed Cruz right before early voting opened in the Texas primary this month.

Two years ago, Palins backing of GOP candidates, including Nevadas Sharron Angle and Delawares Christine ODonnell, seemed less of a positive.

On the other hand, two years ago, Palin endorsed Rick Perry in his reelection bid. He trounced Hutchison, the senator who is now retiring, to win another term as governor.

Lori Stahl covers politics in Texas. You can follow her on Twitter @LoriStahl.