The news that Texas Republican Sen. Kay Bailey Hutchison is not running for reelection will set off a chain reaction, bringing multiple candidates from both parties to compete for the open seat.

Because I always want my readers to be ahead of the conventional wisdom, here is my tip of the month. Keep your eye on the Democratic mayor of San Antonio, Julian Castro, as a rising star in Texas politics. Many Democrats will soon urge him to run for the Senate seat, or to run in the next campaign for governor of Texas.

Castro is a widely respected mayor of a major city. He has been a great mayor and formidable political figure. If and when Castro runs for high office, he will electrify the all-important Hispanic vote, which even Karl Rove will agree is a potentially realigning factor in Texas politics.

Equally important, Julian Castro would have significant crossover voter appeal, would be a credible candidate for political independents, is respected by many in the entrepreneurial Texas business community and would have major fundraising clout.

There will be a number of highly credible names being mentioned, from both parties. I am not predicting Castro runs this time around, but I am predicting he is destined for statewide office and very possibly national attention. Having worked for the late and great Texas Sen. Lloyd Bentsen (D), I am in regular touch with many Texans, and can report there is very serious buzz about Mayor Castro right now.

Does the name Marco RubioMarco Antonio RubioHillicon Valley: Amazon wins union election — says 'our employees made the choice' Overnight Defense: Biden proposes 3B defense budget | Criticism comes in from left and right | Pentagon moves toward new screening for extremists The growing threat of China's lawfare MORE ring a bell? The incoming Republican senator from Florida has already established major credibility, and if he acquits himself well in the Senate, which he may well do, he will quickly join the shortlist of those mentioned for vice president, and maybe more.

Could San Antonio Mayor Julian Castro be the next senator from Texas, or future governor, and the Texas Democratic Marco Rubio?

Things are looking rotten right now for the Texas Democratic Party, but you heard it here: Keep your eye on the very good Democratic mayor of San Antonio, because sooner or later, this gentleman is going places, possibly very big places.