Several Senate races are tight, or at least loud and vicious and interesting to watch. And if the political winds blow in a particular direction in the primaries and again in the general election, a handful of conservative Republicans could take seats in the upper chamber and quickly change the philosophical compass there. A group that includes Gary Polland of Houston, Tommy Williams of The Woodlands, Craig Estes of Wichita Falls, Bob Deuell of Greenville, Ed Harrison of Waxahachie and John Shields of San Antonio is knocking hard on the door. That's a collection that would make the Senate a great deal more conservative than it is now. Deuell's race is in November, against Sen. David Cain, D-Dallas; the five others are in primaries that are likely–because of the way the districts are drawn–to determine who'll win in November. Those districts all lean to the GOP.