With primary elections Tuesday in Texas, we may get the first hint of whether voters are really ready to make major changes in the U.S. Congress, or if sitting lawmakers in both parties are able to withstand challengers who are ready to bring new blood to the halls of the House and Senate.

So far, 38 members of the House and 7 Senators have decided not to return for the 115th Congress which starts next January; for the last five elections between 2004-2012, that is above average for the House, and just about normal for the Senate.

21 House members have decided not to run for re-election this year, while another 17 are seeking other offices.

Usually, not many lawmakers are defeated in primary elections - there were just two in both 2004 and 2006, three in 2008 and four in the big Tea Party year of 2010 - but in 2012, 13 House members went down to defeat before the November elections.

First test in Texas

There are only 13 members of the U.S. House from Texas who have primaries (out of 36 seats), and experts would likely say most of those lawmakers do not have serious challenges.

But a few of these races should be watched as the returns come in - just in case - for a variety of reasons.

Here's a few:

+ 90 year-old Ralph Hall (R-TX) faces off with five GOP challengers, including former U.S. attorney John Ratcliffe, who won the endorsement of the Dallas Morning News.

+ Freshman Rep. Marc Veasey (D-TX) is fighting hard to keep his Fort Worth seat in a Democratic primary challenge by little known candidate Tom Sanchez; Veasey won the endorsement of President Obama last week, maybe a signal of how difficult a race it is.

+ Rep. Mac Thornberry (R-TX) faces two challengers with Tea Party backing who hope to force him into a runoff in his Amarillo area district.

+ Endorsed recently by Sarah Palin, Tea Party activist Katrina Pierson is challenging veteran Rep. Pete Sessions (R-TX). Palin referred to Pierson as a "feisty fighter for freedom."

+ Other incumbents also facing primaries in Texas today are Rep. Sam Johnson (R), Rep. Joe Barton (R), Rep. Kevin Brady (R), Rep. Mike Conaway (R), Rep. Randy Neugebauer (R), Rep. Lamar Smith (R), Rep. Michael Burgess (R) and Rep. Eddie Bernice Johnson (D).

In the U.S. Senate race, Sen. John Cornyn (R-TX) faces seven GOP challengers - he has raised more money and spent more money than all of them combined - but we'll see if attacks on him by Rep. Steve Stockman (R-TX) cause any trouble.

One thing to remember about the Texas vote is that if no candidate gets more than 50 percent of the vote, then there is a two person runoff - and that can often spell trouble for a favorite.

Buckle up. The 2014 mid-term elections are now underway in the Congress.

The November elections are eight months from today.

Remember to follow me Tuesday night on Twitter for election results and analysis - @jamiedupree - every Tuesday night primary night from now until November 4.